Shared library stability improvements

api/api_models/models.go

@@ -0,0 +1,24 @@
+package apimodels
+
+const (
+	BatchOperationTypeCreate  = "Create"
+	BatchOperationTypeDelete  = "Delete"
+	BatchOperationTypeReplace = "Replace"
+	BatchOperationTypeUpsert  = "Upsert"
+	BatchOperationTypeRead    = "Read"
+	BatchOperationTypePatch   = "Patch"
+)
+
+type BatchOperation struct {
+	OperationType string                 `json:"operationType"`
+	Id            string                 `json:"id"`
+	ResourceBody  map[string]interface{} `json:"resourceBody"`
+}
+
+type BatchOperationResult struct {
+	StatusCode    int                    `json:"statusCode"`
+	RequestCharge float64                `json:"requestCharge"`
+	ResourceBody  map[string]interface{} `json:"resourceBody"`
+	Etag          string                 `json:"etag"`
+	Message       string                 `json:"message"`
+}

api/api_server.go

@@ -7,18 +7,21 @@ import (
 )
 
 type ApiServer struct {
-	stopServer chan interface{}
+	stopServer       chan interface{}
-	isActive   bool
+	onServerShutdown chan interface{}
-	router     *gin.Engine
+	isActive         bool
-	config     config.ServerConfig
+	router           *gin.Engine
+	config           config.ServerConfig
 }
 
 func NewApiServer(dataRepository *repositories.DataRepository, config config.ServerConfig) *ApiServer {
 	stopChan := make(chan interface{})
+	onServerShutdownChan := make(chan interface{})
 
 	apiServer := &ApiServer{
-		stopServer: stopChan,
+		stopServer:       stopChan,
-		config:     config,
+		onServerShutdown: onServerShutdownChan,
+		config:           config,
 	}
 
 	apiServer.CreateRouter(dataRepository)
@@ -32,4 +35,5 @@ func (s *ApiServer) GetRouter() *gin.Engine {
 
 func (s *ApiServer) Stop() {
 	s.stopServer <- true
+	<-s.onServerShutdown
 }

api/handlers/documents.go

@@ -8,6 +8,7 @@ import (
 
 	jsonpatch "github.com/cosmiumdev/json-patch/v5"
 	"github.com/gin-gonic/gin"
+	apimodels "github.com/pikami/cosmium/api/api_models"
 	"github.com/pikami/cosmium/internal/constants"
 	"github.com/pikami/cosmium/internal/logger"
 	repositorymodels "github.com/pikami/cosmium/internal/repository_models"
@@ -183,6 +184,13 @@ func (h *Handlers) DocumentsPost(c *gin.Context) {
 	databaseId := c.Param("databaseId")
 	collectionId := c.Param("collId")
 
+	// Handle batch requests
+	isBatchRequest, _ := strconv.ParseBool(c.GetHeader("x-ms-cosmos-is-batch-request"))
+	if isBatchRequest {
+		h.handleBatchRequest(c)
+		return
+	}
+
 	var requestBody map[string]interface{}
 	if err := c.BindJSON(&requestBody); err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"message": err.Error()})
@@ -191,30 +199,7 @@ func (h *Handlers) DocumentsPost(c *gin.Context) {
 
 	query := requestBody["query"]
 	if query != nil {
-		if c.GetHeader("x-ms-cosmos-is-query-plan-request") != "" {
+		h.handleDocumentQuery(c, requestBody)
-			c.IndentedJSON(http.StatusOK, constants.QueryPlanResponse)
-			return
-		}
-
-		var queryParameters map[string]interface{}
-		if paramsArray, ok := requestBody["parameters"].([]interface{}); ok {
-			queryParameters = parametersToMap(paramsArray)
-		}
-
-		docs, status := h.repository.ExecuteQueryDocuments(databaseId, collectionId, query.(string), queryParameters)
-		if status != repositorymodels.StatusOk {
-			// TODO: Currently we return everything if the query fails
-			h.GetAllDocuments(c)
-			return
-		}
-
-		collection, _ := h.repository.GetCollection(databaseId, collectionId)
-		c.Header("x-ms-item-count", fmt.Sprintf("%d", len(docs)))
-		c.IndentedJSON(http.StatusOK, gin.H{
-			"_rid":      collection.ResourceID,
-			"Documents": docs,
-			"_count":    len(docs),
-		})
 		return
 	}
 
@@ -253,3 +238,131 @@ func parametersToMap(pairs []interface{}) map[string]interface{} {
 
 	return result
 }
+
+func (h *Handlers) handleDocumentQuery(c *gin.Context, requestBody map[string]interface{}) {
+	databaseId := c.Param("databaseId")
+	collectionId := c.Param("collId")
+
+	if c.GetHeader("x-ms-cosmos-is-query-plan-request") != "" {
+		c.IndentedJSON(http.StatusOK, constants.QueryPlanResponse)
+		return
+	}
+
+	var queryParameters map[string]interface{}
+	if paramsArray, ok := requestBody["parameters"].([]interface{}); ok {
+		queryParameters = parametersToMap(paramsArray)
+	}
+
+	docs, status := h.repository.ExecuteQueryDocuments(databaseId, collectionId, requestBody["query"].(string), queryParameters)
+	if status != repositorymodels.StatusOk {
+		// TODO: Currently we return everything if the query fails
+		h.GetAllDocuments(c)
+		return
+	}
+
+	collection, _ := h.repository.GetCollection(databaseId, collectionId)
+	c.Header("x-ms-item-count", fmt.Sprintf("%d", len(docs)))
+	c.IndentedJSON(http.StatusOK, gin.H{
+		"_rid":      collection.ResourceID,
+		"Documents": docs,
+		"_count":    len(docs),
+	})
+}
+
+func (h *Handlers) handleBatchRequest(c *gin.Context) {
+	databaseId := c.Param("databaseId")
+	collectionId := c.Param("collId")
+
+	batchOperations := make([]apimodels.BatchOperation, 0)
+	if err := c.BindJSON(&batchOperations); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"message": err.Error()})
+		return
+	}
+
+	batchOperationResults := make([]apimodels.BatchOperationResult, len(batchOperations))
+	for idx, operation := range batchOperations {
+		switch operation.OperationType {
+		case apimodels.BatchOperationTypeCreate:
+			createdDocument, status := h.repository.CreateDocument(databaseId, collectionId, operation.ResourceBody)
+			responseCode := repositoryStatusToResponseCode(status)
+			if status == repositorymodels.StatusOk {
+				responseCode = http.StatusCreated
+			}
+			batchOperationResults[idx] = apimodels.BatchOperationResult{
+				StatusCode:   responseCode,
+				ResourceBody: createdDocument,
+			}
+		case apimodels.BatchOperationTypeDelete:
+			status := h.repository.DeleteDocument(databaseId, collectionId, operation.Id)
+			responseCode := repositoryStatusToResponseCode(status)
+			if status == repositorymodels.StatusOk {
+				responseCode = http.StatusNoContent
+			}
+			batchOperationResults[idx] = apimodels.BatchOperationResult{
+				StatusCode: responseCode,
+			}
+		case apimodels.BatchOperationTypeReplace:
+			deleteStatus := h.repository.DeleteDocument(databaseId, collectionId, operation.Id)
+			if deleteStatus == repositorymodels.StatusNotFound {
+				batchOperationResults[idx] = apimodels.BatchOperationResult{
+					StatusCode: http.StatusNotFound,
+				}
+				continue
+			}
+			createdDocument, createStatus := h.repository.CreateDocument(databaseId, collectionId, operation.ResourceBody)
+			responseCode := repositoryStatusToResponseCode(createStatus)
+			if createStatus == repositorymodels.StatusOk {
+				responseCode = http.StatusCreated
+			}
+			batchOperationResults[idx] = apimodels.BatchOperationResult{
+				StatusCode:   responseCode,
+				ResourceBody: createdDocument,
+			}
+		case apimodels.BatchOperationTypeUpsert:
+			documentId := operation.ResourceBody["id"].(string)
+			h.repository.DeleteDocument(databaseId, collectionId, documentId)
+			createdDocument, createStatus := h.repository.CreateDocument(databaseId, collectionId, operation.ResourceBody)
+			responseCode := repositoryStatusToResponseCode(createStatus)
+			if createStatus == repositorymodels.StatusOk {
+				responseCode = http.StatusCreated
+			}
+			batchOperationResults[idx] = apimodels.BatchOperationResult{
+				StatusCode:   responseCode,
+				ResourceBody: createdDocument,
+			}
+		case apimodels.BatchOperationTypeRead:
+			document, status := h.repository.GetDocument(databaseId, collectionId, operation.Id)
+			batchOperationResults[idx] = apimodels.BatchOperationResult{
+				StatusCode:   repositoryStatusToResponseCode(status),
+				ResourceBody: document,
+			}
+		case apimodels.BatchOperationTypePatch:
+			batchOperationResults[idx] = apimodels.BatchOperationResult{
+				StatusCode: http.StatusNotImplemented,
+				Message:    "Patch operation is not implemented",
+			}
+		default:
+			batchOperationResults[idx] = apimodels.BatchOperationResult{
+				StatusCode: http.StatusBadRequest,
+				Message:    "Unknown operation type",
+			}
+		}
+	}
+
+	c.JSON(http.StatusOK, batchOperationResults)
+}
+
+func repositoryStatusToResponseCode(status repositorymodels.RepositoryStatus) int {
+	switch status {
+	case repositorymodels.StatusOk:
+		return http.StatusOK
+	case repositorymodels.StatusNotFound:
+		return http.StatusNotFound
+	case repositorymodels.Conflict:
+		return http.StatusConflict
+	case repositorymodels.BadRequest:
+		return http.StatusBadRequest
+	default:
+		return http.StatusInternalServerError
+	}
+}

api/handlers/middleware/authentication.go

@@ -75,8 +75,7 @@ func requestToResourceId(c *gin.Context) string {
 
 	isFeed := c.Request.Header.Get("A-Im") == "Incremental Feed"
 	if resourceType == "pkranges" && isFeed {
-		// CosmosSDK replaces '/' with '-' in resource id requests
+		resourceId = collId
-		resourceId = strings.Replace(collId, "-", "/", -1)
 	}
 
 	return resourceId

api/handlers/partition_key_ranges.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/gin-gonic/gin"
 	repositorymodels "github.com/pikami/cosmium/internal/repository_models"
+	"github.com/pikami/cosmium/internal/resourceid"
 )
 
 func (h *Handlers) GetPartitionKeyRanges(c *gin.Context) {
@@ -31,8 +32,9 @@ func (h *Handlers) GetPartitionKeyRanges(c *gin.Context) {
 			collectionRid = collection.ResourceID
 		}
 
+		rid := resourceid.NewCombined(collectionRid, resourceid.New(resourceid.ResourceTypePartitionKeyRange))
 		c.IndentedJSON(http.StatusOK, gin.H{
-			"_rid":               collectionRid,
+			"_rid":               rid,
 			"_count":             len(partitionKeyRanges),
 			"PartitionKeyRanges": partitionKeyRanges,
 		})

api/router.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/http"
 	"sync"
+	"time"
 
 	"github.com/gin-gonic/gin"
 	"github.com/pikami/cosmium/api/handlers"
@@ -86,7 +87,7 @@ func (s *ApiServer) CreateRouter(repository *repositories.DataRepository) {
 	s.router = router
 }
 
-func (s *ApiServer) Start() {
+func (s *ApiServer) Start() error {
 	listenAddress := fmt.Sprintf(":%d", s.config.Port)
 	s.isActive = true
 
@@ -95,6 +96,8 @@ func (s *ApiServer) Start() {
 		Handler: s.router.Handler(),
 	}
 
+	errChan := make(chan error, 1)
+
 	go func() {
 		<-s.stopServer
 		logger.InfoLn("Shutting down server...")
@@ -102,35 +105,40 @@ func (s *ApiServer) Start() {
 		if err != nil {
 			logger.ErrorLn("Failed to shutdown server:", err)
 		}
+		s.onServerShutdown <- true
 	}()
 
 	go func() {
+		var err error
 		if s.config.DisableTls {
 			logger.Infof("Listening and serving HTTP on %s\n", server.Addr)
-			err := server.ListenAndServe()
+			err = server.ListenAndServe()
-			if err != nil && err != http.ErrServerClosed {
-				logger.ErrorLn("Failed to start HTTP server:", err)
-			}
-			s.isActive = false
 		} else if s.config.TLS_CertificatePath != "" && s.config.TLS_CertificateKey != "" {
 			logger.Infof("Listening and serving HTTPS on %s\n", server.Addr)
-			err := server.ListenAndServeTLS(
+			err = server.ListenAndServeTLS(
 				s.config.TLS_CertificatePath,
 				s.config.TLS_CertificateKey)
-			if err != nil && err != http.ErrServerClosed {
-				logger.ErrorLn("Failed to start HTTPS server:", err)
-			}
-			s.isActive = false
 		} else {
 			tlsConfig := tlsprovider.GetDefaultTlsConfig()
 			server.TLSConfig = tlsConfig
 
 			logger.Infof("Listening and serving HTTPS on %s\n", server.Addr)
-			err := server.ListenAndServeTLS("", "")
+			err = server.ListenAndServeTLS("", "")
-			if err != nil && err != http.ErrServerClosed {
-				logger.ErrorLn("Failed to start HTTPS server:", err)
-			}
-			s.isActive = false
 		}
+
+		if err != nil && err != http.ErrServerClosed {
+			logger.ErrorLn("Failed to start server:", err)
+			errChan <- err
+		} else {
+			errChan <- nil
+		}
+		s.isActive = false
 	}()
+
+	select {
+	case err := <-errChan:
+		return err
+	case <-time.After(50 * time.Millisecond):
+		return nil
+	}
 }

api/tests/config_test.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/pikami/cosmium/api"
 	"github.com/pikami/cosmium/api/config"
+	"github.com/pikami/cosmium/internal/logger"
 	"github.com/pikami/cosmium/internal/repositories"
 )
 
@@ -35,6 +36,9 @@ func runTestServer() *TestServer {
 		ExplorerBaseUrlLocation: config.ExplorerBaseUrlLocation,
 	}
 
+	config.LogLevel = "debug"
+	logger.SetLogLevel(logger.LogLevelDebug)
+
 	return runTestServerCustomConfig(config)
 }
 

api/tests/documents_test.go

@@ -377,5 +377,140 @@ func Test_Documents_Patch(t *testing.T) {
 		assert.NotNil(t, r)
 		assert.Nil(t, err2)
 	})
-
+}
+
+func Test_Documents_TransactionalBatch(t *testing.T) {
+	ts, collectionClient := documents_InitializeDb(t)
+	defer ts.Server.Close()
+
+	t.Run("Should execute CREATE transactional batch", func(t *testing.T) {
+		context := context.TODO()
+		batch := collectionClient.NewTransactionalBatch(azcosmos.NewPartitionKeyString("pk"))
+
+		newItem := map[string]interface{}{
+			"id": "678901",
+		}
+		bytes, err := json.Marshal(newItem)
+		assert.Nil(t, err)
+
+		batch.CreateItem(bytes, nil)
+		response, err := collectionClient.ExecuteTransactionalBatch(context, batch, &azcosmos.TransactionalBatchOptions{})
+		assert.Nil(t, err)
+		assert.True(t, response.Success)
+		assert.Equal(t, 1, len(response.OperationResults))
+
+		operationResponse := response.OperationResults[0]
+		assert.NotNil(t, operationResponse)
+		assert.NotNil(t, operationResponse.ResourceBody)
+		assert.Equal(t, int32(http.StatusCreated), operationResponse.StatusCode)
+
+		var itemResponseBody map[string]interface{}
+		json.Unmarshal(operationResponse.ResourceBody, &itemResponseBody)
+		assert.Equal(t, newItem["id"], itemResponseBody["id"])
+
+		createdDoc, _ := ts.Repository.GetDocument(testDatabaseName, testCollectionName, newItem["id"].(string))
+		assert.Equal(t, newItem["id"], createdDoc["id"])
+	})
+
+	t.Run("Should execute DELETE transactional batch", func(t *testing.T) {
+		context := context.TODO()
+		batch := collectionClient.NewTransactionalBatch(azcosmos.NewPartitionKeyString("pk"))
+
+		batch.DeleteItem("12345", nil)
+		response, err := collectionClient.ExecuteTransactionalBatch(context, batch, &azcosmos.TransactionalBatchOptions{})
+		assert.Nil(t, err)
+		assert.True(t, response.Success)
+		assert.Equal(t, 1, len(response.OperationResults))
+
+		operationResponse := response.OperationResults[0]
+		assert.NotNil(t, operationResponse)
+		assert.Equal(t, int32(http.StatusNoContent), operationResponse.StatusCode)
+
+		_, status := ts.Repository.GetDocument(testDatabaseName, testCollectionName, "12345")
+		assert.Equal(t, repositorymodels.StatusNotFound, int(status))
+	})
+
+	t.Run("Should execute REPLACE transactional batch", func(t *testing.T) {
+		context := context.TODO()
+		batch := collectionClient.NewTransactionalBatch(azcosmos.NewPartitionKeyString("pk"))
+
+		newItem := map[string]interface{}{
+			"id": "67890",
+			"pk": "666",
+		}
+		bytes, err := json.Marshal(newItem)
+		assert.Nil(t, err)
+
+		batch.ReplaceItem("67890", bytes, nil)
+		response, err := collectionClient.ExecuteTransactionalBatch(context, batch, &azcosmos.TransactionalBatchOptions{})
+		assert.Nil(t, err)
+		assert.True(t, response.Success)
+		assert.Equal(t, 1, len(response.OperationResults))
+
+		operationResponse := response.OperationResults[0]
+		assert.NotNil(t, operationResponse)
+		assert.NotNil(t, operationResponse.ResourceBody)
+		assert.Equal(t, int32(http.StatusCreated), operationResponse.StatusCode)
+
+		var itemResponseBody map[string]interface{}
+		json.Unmarshal(operationResponse.ResourceBody, &itemResponseBody)
+		assert.Equal(t, newItem["id"], itemResponseBody["id"])
+		assert.Equal(t, newItem["pk"], itemResponseBody["pk"])
+
+		updatedDoc, _ := ts.Repository.GetDocument(testDatabaseName, testCollectionName, newItem["id"].(string))
+		assert.Equal(t, newItem["id"], updatedDoc["id"])
+		assert.Equal(t, newItem["pk"], updatedDoc["pk"])
+	})
+
+	t.Run("Should execute UPSERT transactional batch", func(t *testing.T) {
+		context := context.TODO()
+		batch := collectionClient.NewTransactionalBatch(azcosmos.NewPartitionKeyString("pk"))
+
+		newItem := map[string]interface{}{
+			"id": "678901",
+			"pk": "666",
+		}
+		bytes, err := json.Marshal(newItem)
+		assert.Nil(t, err)
+
+		batch.UpsertItem(bytes, nil)
+		response, err := collectionClient.ExecuteTransactionalBatch(context, batch, &azcosmos.TransactionalBatchOptions{})
+		assert.Nil(t, err)
+		assert.True(t, response.Success)
+		assert.Equal(t, 1, len(response.OperationResults))
+
+		operationResponse := response.OperationResults[0]
+		assert.NotNil(t, operationResponse)
+		assert.NotNil(t, operationResponse.ResourceBody)
+		assert.Equal(t, int32(http.StatusCreated), operationResponse.StatusCode)
+
+		var itemResponseBody map[string]interface{}
+		json.Unmarshal(operationResponse.ResourceBody, &itemResponseBody)
+		assert.Equal(t, newItem["id"], itemResponseBody["id"])
+		assert.Equal(t, newItem["pk"], itemResponseBody["pk"])
+
+		updatedDoc, _ := ts.Repository.GetDocument(testDatabaseName, testCollectionName, newItem["id"].(string))
+		assert.Equal(t, newItem["id"], updatedDoc["id"])
+		assert.Equal(t, newItem["pk"], updatedDoc["pk"])
+	})
+
+	t.Run("Should execute READ transactional batch", func(t *testing.T) {
+		context := context.TODO()
+		batch := collectionClient.NewTransactionalBatch(azcosmos.NewPartitionKeyString("pk"))
+
+		batch.ReadItem("67890", nil)
+		response, err := collectionClient.ExecuteTransactionalBatch(context, batch, &azcosmos.TransactionalBatchOptions{})
+		assert.Nil(t, err)
+		assert.True(t, response.Success)
+		assert.Equal(t, 1, len(response.OperationResults))
+
+		operationResponse := response.OperationResults[0]
+		assert.NotNil(t, operationResponse)
+		assert.NotNil(t, operationResponse.ResourceBody)
+		assert.Equal(t, int32(http.StatusOK), operationResponse.StatusCode)
+
+		var itemResponseBody map[string]interface{}
+		json.Unmarshal(operationResponse.ResourceBody, &itemResponseBody)
+		assert.Equal(t, "67890", itemResponseBody["id"])
+	})
 }

cmd/server/server.go

@@ -19,7 +19,10 @@ func main() {
 	})
 
 	server := api.NewApiServer(repository, configuration)
-	server.Start()
+	err := server.Start()
+	if err != nil {
+		panic(err)
+	}
 
 	waitForExit(server, repository, configuration)
 }

docs/COMPATIBILITY.md

@@ -204,6 +204,19 @@ Cosmium strives to support the core features of Cosmos DB, including:
 | IS_PRIMITIVE     | Yes         |
 | IS_STRING        | Yes         |
 
+### Transactional batch operations
+
+Note: There's actually no transaction here. Think of this as a 'bulk operation' that can partially succeed.
+
+| Operation | Implemented |
+| --------- | ----------- |
+| Create    | Yes         |
+| Delete    | Yes         |
+| Replace   | Yes         |
+| Upsert    | Yes         |
+| Read      | Yes         |
+| Patch     | No          |
+
 ## Known Differences
 
 While Cosmium aims to replicate the behavior of Cosmos DB as closely as possible, there are certain differences and limitations to be aware of:

internal/repositories/collections.go

@@ -50,6 +50,10 @@ func (r *DataRepository) DeleteCollection(databaseId string, collectionId string
 	}
 
 	delete(r.storeState.Collections[databaseId], collectionId)
+	delete(r.storeState.Documents[databaseId], collectionId)
+	delete(r.storeState.Triggers[databaseId], collectionId)
+	delete(r.storeState.StoredProcedures[databaseId], collectionId)
+	delete(r.storeState.UserDefinedFunctions[databaseId], collectionId)
 
 	return repositorymodels.StatusOk
 }
@@ -71,7 +75,7 @@ func (r *DataRepository) CreateCollection(databaseId string, newCollection repos
 	newCollection = structhidrators.Hidrate(newCollection).(repositorymodels.Collection)
 
 	newCollection.TimeStamp = time.Now().Unix()
-	newCollection.ResourceID = resourceid.NewCombined(database.ResourceID, resourceid.New())
+	newCollection.ResourceID = resourceid.NewCombined(database.ResourceID, resourceid.New(resourceid.ResourceTypeCollection))
 	newCollection.ETag = fmt.Sprintf("\"%s\"", uuid.New())
 	newCollection.Self = fmt.Sprintf("dbs/%s/colls/%s/", database.ResourceID, newCollection.ResourceID)
 

internal/repositories/databases.go

@@ -37,6 +37,11 @@ func (r *DataRepository) DeleteDatabase(id string) repositorymodels.RepositorySt
 	}
 
 	delete(r.storeState.Databases, id)
+	delete(r.storeState.Collections, id)
+	delete(r.storeState.Documents, id)
+	delete(r.storeState.Triggers, id)
+	delete(r.storeState.StoredProcedures, id)
+	delete(r.storeState.UserDefinedFunctions, id)
 
 	return repositorymodels.StatusOk
 }
@@ -50,7 +55,7 @@ func (r *DataRepository) CreateDatabase(newDatabase repositorymodels.Database) (
 	}
 
 	newDatabase.TimeStamp = time.Now().Unix()
-	newDatabase.ResourceID = resourceid.New()
+	newDatabase.ResourceID = resourceid.New(resourceid.ResourceTypeDatabase)
 	newDatabase.ETag = fmt.Sprintf("\"%s\"", uuid.New())
 	newDatabase.Self = fmt.Sprintf("dbs/%s/", newDatabase.ResourceID)
 

internal/repositories/documents.go

@@ -95,7 +95,7 @@ func (r *DataRepository) CreateDocument(databaseId string, collectionId string,
 	}
 
 	document["_ts"] = time.Now().Unix()
-	document["_rid"] = resourceid.NewCombined(database.ResourceID, collection.ResourceID, resourceid.New())
+	document["_rid"] = resourceid.NewCombined(collection.ResourceID, resourceid.New(resourceid.ResourceTypeDocument))
 	document["_etag"] = fmt.Sprintf("\"%s\"", uuid.New())
 	document["_self"] = fmt.Sprintf("dbs/%s/colls/%s/docs/%s/", database.ResourceID, collection.ResourceID, document["_rid"])
 

internal/repositories/partition_key_ranges.go

@@ -26,7 +26,7 @@ func (r *DataRepository) GetPartitionKeyRanges(databaseId string, collectionId s
 		timestamp = collection.TimeStamp
 	}
 
-	pkrResourceId := resourceid.NewCombined(databaseRid, collectionRid, resourceid.New())
+	pkrResourceId := resourceid.NewCombined(collectionRid, resourceid.New(resourceid.ResourceTypePartitionKeyRange))
 	pkrSelf := fmt.Sprintf("dbs/%s/colls/%s/pkranges/%s/", databaseRid, collectionRid, pkrResourceId)
 	etag := fmt.Sprintf("\"%s\"", uuid.New())
 

internal/repositories/stored_procedures.go

@@ -81,7 +81,7 @@ func (r *DataRepository) CreateStoredProcedure(databaseId string, collectionId s
 	}
 
 	sp.TimeStamp = time.Now().Unix()
-	sp.ResourceID = resourceid.NewCombined(database.ResourceID, collection.ResourceID, resourceid.New())
+	sp.ResourceID = resourceid.NewCombined(collection.ResourceID, resourceid.New(resourceid.ResourceTypeStoredProcedure))
 	sp.ETag = fmt.Sprintf("\"%s\"", uuid.New())
 	sp.Self = fmt.Sprintf("dbs/%s/colls/%s/sprocs/%s/", database.ResourceID, collection.ResourceID, sp.ResourceID)
 

internal/repositories/triggers.go

@@ -81,7 +81,7 @@ func (r *DataRepository) CreateTrigger(databaseId string, collectionId string, t
 	}
 
 	trigger.TimeStamp = time.Now().Unix()
-	trigger.ResourceID = resourceid.NewCombined(database.ResourceID, collection.ResourceID, resourceid.New())
+	trigger.ResourceID = resourceid.NewCombined(collection.ResourceID, resourceid.New(resourceid.ResourceTypeTrigger))
 	trigger.ETag = fmt.Sprintf("\"%s\"", uuid.New())
 	trigger.Self = fmt.Sprintf("dbs/%s/colls/%s/triggers/%s/", database.ResourceID, collection.ResourceID, trigger.ResourceID)
 

internal/repositories/user_defined_functions.go

@@ -81,7 +81,7 @@ func (r *DataRepository) CreateUserDefinedFunction(databaseId string, collection
 	}
 
 	udf.TimeStamp = time.Now().Unix()
-	udf.ResourceID = resourceid.NewCombined(database.ResourceID, collection.ResourceID, resourceid.New())
+	udf.ResourceID = resourceid.NewCombined(collection.ResourceID, resourceid.New(resourceid.ResourceTypeUserDefinedFunction))
 	udf.ETag = fmt.Sprintf("\"%s\"", uuid.New())
 	udf.Self = fmt.Sprintf("dbs/%s/colls/%s/udfs/%s/", database.ResourceID, collection.ResourceID, udf.ResourceID)
 

internal/resourceid/resourceid.go

@@ -3,32 +3,76 @@ package resourceid
 import (
 	"encoding/base64"
 	"math/rand"
+	"strings"
 
 	"github.com/google/uuid"
 )
 
-func New() string {
+type ResourceType int
-	id := uuid.New().ID()
-	idBytes := uintToBytes(id)
 
-	// first byte should be bigger than 0x80 for collection ids
+const (
-	// clients classify this id as "user" otherwise
+	ResourceTypeDatabase ResourceType = iota
-	if (idBytes[0] & 0x80) <= 0 {
+	ResourceTypeCollection
-		idBytes[0] = byte(rand.Intn(0x80) + 0x80)
+	ResourceTypeDocument
+	ResourceTypeStoredProcedure
+	ResourceTypeTrigger
+	ResourceTypeUserDefinedFunction
+	ResourceTypeConflict
+	ResourceTypePartitionKeyRange
+	ResourceTypeSchema
+)
+
+func New(resourceType ResourceType) string {
+	var idBytes []byte
+	switch resourceType {
+	case ResourceTypeDatabase:
+		idBytes = randomBytes(4)
+	case ResourceTypeCollection:
+		idBytes = randomBytes(4)
+		// first byte should be bigger than 0x80 for collection ids
+		// clients classify this id as "user" otherwise
+		if (idBytes[0] & 0x80) <= 0 {
+			idBytes[0] = byte(rand.Intn(0x80) + 0x80)
+		}
+	case ResourceTypeDocument:
+		idBytes = randomBytes(8)
+		idBytes[7] = byte(rand.Intn(0x10)) // Upper 4 bits = 0
+	case ResourceTypeStoredProcedure:
+		idBytes = randomBytes(8)
+		idBytes[7] = byte(rand.Intn(0x10)) | 0x08 // Upper 4 bits = 0x08
+	case ResourceTypeTrigger:
+		idBytes = randomBytes(8)
+		idBytes[7] = byte(rand.Intn(0x10)) | 0x07 // Upper 4 bits = 0x07
+	case ResourceTypeUserDefinedFunction:
+		idBytes = randomBytes(8)
+		idBytes[7] = byte(rand.Intn(0x10)) | 0x06 // Upper 4 bits = 0x06
+	case ResourceTypeConflict:
+		idBytes = randomBytes(8)
+		idBytes[7] = byte(rand.Intn(0x10)) | 0x04 // Upper 4 bits = 0x04
+	case ResourceTypePartitionKeyRange:
+		// we don't do partitions yet, so just use a fixed id
+		idBytes = []byte{0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x50}
+	case ResourceTypeSchema:
+		idBytes = randomBytes(8)
+		idBytes[7] = byte(rand.Intn(0x10)) | 0x09 // Upper 4 bits = 0x09
+	default:
+		idBytes = randomBytes(4)
 	}
 
-	return base64.StdEncoding.EncodeToString(idBytes)
+	encoded := base64.StdEncoding.EncodeToString(idBytes)
+	return strings.ReplaceAll(encoded, "/", "-")
 }
 
 func NewCombined(ids ...string) string {
 	combinedIdBytes := make([]byte, 0)
 
 	for _, id := range ids {
-		idBytes, _ := base64.StdEncoding.DecodeString(id)
+		idBytes, _ := base64.StdEncoding.DecodeString(strings.ReplaceAll(id, "-", "/"))
 		combinedIdBytes = append(combinedIdBytes, idBytes...)
 	}
 
-	return base64.StdEncoding.EncodeToString(combinedIdBytes)
+	encoded := base64.StdEncoding.EncodeToString(combinedIdBytes)
+	return strings.ReplaceAll(encoded, "/", "-")
 }
 
 func uintToBytes(id uint32) []byte {
@@ -39,3 +83,13 @@ func uintToBytes(id uint32) []byte {
 
 	return buf
 }
+
+func randomBytes(count int) []byte {
+	buf := make([]byte, count)
+	for i := 0; i < count; i += 4 {
+		id := uuid.New().ID()
+		idBytes := uintToBytes(id)
+		copy(buf[i:], idBytes)
+	}
+	return buf
+}

parsers/models.go

@@ -17,6 +17,7 @@ type SelectStmt struct {
 type Table struct {
 	Value      string
 	SelectItem SelectItem
+	IsInSelect bool
 }
 
 type JoinItem struct {

parsers/nosql/aggregate_functions_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/pikami/cosmium/parsers"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Parse_AggregateFunctions(t *testing.T) {
@@ -27,7 +28,7 @@ func Test_Parse_AggregateFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -51,7 +52,7 @@ func Test_Parse_AggregateFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -75,7 +76,7 @@ func Test_Parse_AggregateFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -99,7 +100,7 @@ func Test_Parse_AggregateFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -123,7 +124,7 @@ func Test_Parse_AggregateFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})

parsers/nosql/array_functions_test.go

@@ -32,7 +32,7 @@ func Test_Parse_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -58,7 +58,7 @@ func Test_Parse_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -87,7 +87,7 @@ func Test_Parse_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -116,7 +116,7 @@ func Test_Parse_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -145,7 +145,7 @@ func Test_Parse_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -169,7 +169,7 @@ func Test_Parse_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -195,7 +195,7 @@ func Test_Parse_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -223,7 +223,7 @@ func Test_Parse_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -251,7 +251,7 @@ func Test_Parse_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})

parsers/nosql/join_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/pikami/cosmium/parsers"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Parse_Join(t *testing.T) {
@@ -17,7 +18,7 @@ func Test_Parse_Join(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "pk"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				JoinItems: []parsers.JoinItem{
 					{
 						Table: parsers.Table{
@@ -40,7 +41,7 @@ func Test_Parse_Join(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"cc"}, IsTopLevel: true},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				JoinItems: []parsers.JoinItem{
 					{
 						Table: parsers.Table{

parsers/nosql/math_functions_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/pikami/cosmium/parsers"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Execute_MathFunctions(t *testing.T) {
@@ -644,7 +645,7 @@ func testMathFunctionParse(
 					},
 				},
 			},
-			Table: parsers.Table{Value: expectedTable},
+			Table: parsers.Table{SelectItem: testutils.SelectItem_Path(expectedTable)},
 		},
 	)
 }

parsers/nosql/misc_test.go

@@ -49,7 +49,7 @@ func Test_Parse(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "pk"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				OrderExpressions: []parsers.OrderExpression{
 					{
 						SelectItem: parsers.SelectItem{Path: []string{"c", "id"}},
@@ -73,7 +73,7 @@ func Test_Parse(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "pk"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				GroupBy: []parsers.SelectItem{
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "pk"}},
@@ -93,7 +93,7 @@ func Test_Parse(t *testing.T) {
 						Type: parsers.SelectItemTypeField,
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -124,10 +124,9 @@ func Test_Parse(t *testing.T) {
 					},
 				},
 				Table: parsers.Table{
-					Value: "c",
+					Value:      "c",
-					SelectItem: parsers.SelectItem{
+					SelectItem: testutils.SelectItem_Path("c", "tags"),
-						Path: []string{"c", "tags"},
+					IsInSelect: true,
-					},
 				},
 			},
 		)

parsers/nosql/nosql.peg

@@ -204,14 +204,22 @@ TopClause <- Top ws count:Integer {
     return count, nil
 }
 
-FromClause <- From ws table:TableName selectItem:(ws "IN"i ws column:SelectItem { return column, nil })? {
+FromClause <- From ws table:TableName selectItem:(ws In ws column:SelectItem { return column, nil }) {
     tableTyped := table.(parsers.Table)
 
     if selectItem != nil {
 	    tableTyped.SelectItem = selectItem.(parsers.SelectItem)
+        tableTyped.IsInSelect = true
 	}
 
 	return tableTyped, nil
+} / From ws column:SelectItem {
+    tableSelectItem := column.(parsers.SelectItem)
+    table := parsers.Table{
+        Value: tableSelectItem.Alias,
+        SelectItem: tableSelectItem,
+    }
+    return table, nil
 } / From ws subQuery:SubQuerySelectItem {
     subQueryTyped := subQuery.(parsers.SelectItem)
 	table := parsers.Table{
@@ -243,13 +251,13 @@ SubQuerySelectItem <- subQuery:SubQuery asClause:(ws alias:AsClause { return ali
     return selectItem, nil
 }
 
-JoinClause <- Join ws table:TableName ws "IN"i ws column:SelectItem {
+JoinClause <- Join ws table:TableName ws In ws column:SelectItem {
     return makeJoin(table, column)
 } / Join ws subQuery:SubQuerySelectItem {
     return makeJoin(nil, subQuery)
 }
 
-OffsetClause <- "OFFSET"i ws offset:IntegerLiteral ws "LIMIT"i ws limit:IntegerLiteral {
+OffsetClause <- Offset ws offset:IntegerLiteral ws "LIMIT"i ws limit:IntegerLiteral {
     return []interface{}{offset.(parsers.Constant).Value, limit.(parsers.Constant).Value}, nil
 }
 
@@ -317,7 +325,11 @@ SelectItem <- selectItem:(SubQuerySelectItem / Literal / FunctionCall / SelectAr
 	return itemResult, nil
 }
 
-AsClause <- ws As ws alias:Identifier { return alias, nil }
+AsClause <- (ws As)? ws !ExcludedKeywords alias:Identifier {
+    return alias, nil
+}
+
+ExcludedKeywords <- Select / Top / As / From / In / Join / Exists / Where / And / Or / GroupBy / OrderBy / Offset
 
 DotFieldAccess <- "." id:Identifier {
     return id, nil
@@ -373,6 +385,8 @@ As <- "AS"i
 
 From <- "FROM"i
 
+In <- "IN"i
+
 Join <- "JOIN"i
 
 Exists <- "EXISTS"i
@@ -387,6 +401,8 @@ GroupBy <- "GROUP"i ws "BY"i
 
 OrderBy <- "ORDER"i ws "BY"i
 
+Offset <- "OFFSET"i
+
 ComparisonOperator <- ("=" / "!=" / "<" / "<=" / ">" / ">=") {
     return string(c.text), nil
 }
@@ -700,7 +716,7 @@ MathNumberBinExpression <- "NumberBin"i ws "(" ws ex1:SelectItem others:(ws ","
 MathPiExpression <- "PI"i ws "(" ws ")" { return createFunctionCall(parsers.FunctionCallMathPi, []interface{}{}) }
 MathRandExpression <- "RAND"i ws "(" ws ")" { return createFunctionCall(parsers.FunctionCallMathRand, []interface{}{}) }
 
-InFunction <- ex1:SelectProperty ws "IN"i ws "(" ws ex2:SelectItem others:(ws "," ws ex:SelectItem { return ex, nil })* ws ")" {
+InFunction <- ex1:SelectProperty ws In ws "(" ws ex2:SelectItem others:(ws "," ws ex:SelectItem { return ex, nil })* ws ")" {
     return createFunctionCall(parsers.FunctionCallIn, append([]interface{}{ex1, ex2}, others.([]interface{})...))
 }
 

parsers/nosql/select_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/pikami/cosmium/parsers"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Parse_Select(t *testing.T) {
@@ -17,7 +18,7 @@ func Test_Parse_Select(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "pk"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -31,7 +32,7 @@ func Test_Parse_Select(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "@param"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -44,7 +45,7 @@ func Test_Parse_Select(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "id"}},
 				},
-				Table:    parsers.Table{Value: "c"},
+				Table:    parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Distinct: true,
 			},
 		)
@@ -58,7 +59,7 @@ func Test_Parse_Select(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "id"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Count: 1,
 			},
 		)
@@ -72,7 +73,7 @@ func Test_Parse_Select(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "id"}},
 				},
-				Table:  parsers.Table{Value: "c"},
+				Table:  parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Count:  5,
 				Offset: 3,
 			},
@@ -87,7 +88,7 @@ func Test_Parse_Select(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "id"}, IsTopLevel: true},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -100,7 +101,20 @@ func Test_Parse_Select(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c"}, IsTopLevel: true},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
+			},
+		)
+	})
+
+	t.Run("Should parse SELECT c", func(t *testing.T) {
+		testQueryParse(
+			t,
+			`SELECT c FROM c`,
+			parsers.SelectStmt{
+				SelectItems: []parsers.SelectItem{
+					{Path: []string{"c"}, IsTopLevel: false},
+				},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -120,7 +134,27 @@ func Test_Parse_Select(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
+			},
+		)
+	})
+
+	t.Run("Should parse SELECT with alias", func(t *testing.T) {
+		testQueryParse(
+			t,
+			`SELECT
+			  c.id AS aliasWithAs,
+			  c.pk aliasWithoutAs
+			FROM root c`,
+			parsers.SelectStmt{
+				SelectItems: []parsers.SelectItem{
+					{Alias: "aliasWithAs", Path: []string{"c", "id"}},
+					{Alias: "aliasWithoutAs", Path: []string{"c", "pk"}},
+				},
+				Table: parsers.Table{
+					Value:      "c",
+					SelectItem: parsers.SelectItem{Alias: "c", Path: []string{"root"}},
+				},
 			},
 		)
 	})
@@ -140,7 +174,7 @@ func Test_Parse_Select(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})

parsers/nosql/string_functions_test.go

@@ -30,7 +30,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -56,7 +56,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -85,7 +85,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -111,7 +111,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -137,7 +137,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -163,7 +163,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -189,7 +189,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -213,7 +213,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -237,7 +237,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -261,7 +261,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -286,7 +286,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -310,7 +310,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -334,7 +334,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -360,7 +360,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -385,7 +385,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -409,7 +409,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -434,7 +434,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -458,7 +458,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -484,7 +484,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})
@@ -508,7 +508,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 		)
 	})

parsers/nosql/subquery_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/pikami/cosmium/parsers"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Parse_SubQuery(t *testing.T) {
@@ -22,7 +23,7 @@ func Test_Parse_SubQuery(t *testing.T) {
 						Alias: "c",
 						Type:  parsers.SelectItemTypeSubQuery,
 						Value: parsers.SelectStmt{
-							Table: parsers.Table{Value: "cc"},
+							Table: parsers.Table{SelectItem: testutils.SelectItem_Path("cc")},
 							SelectItems: []parsers.SelectItem{
 								{Path: []string{"cc", "info"}, IsTopLevel: true},
 							},
@@ -42,9 +43,7 @@ func Test_Parse_SubQuery(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"cc", "name"}},
 				},
-				Table: parsers.Table{
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
-					Value: "c",
-				},
 				JoinItems: []parsers.JoinItem{
 					{
 						Table: parsers.Table{
@@ -55,13 +54,12 @@ func Test_Parse_SubQuery(t *testing.T) {
 							Type:  parsers.SelectItemTypeSubQuery,
 							Value: parsers.SelectStmt{
 								SelectItems: []parsers.SelectItem{
-									{Path: []string{"tag", "name"}},
+									testutils.SelectItem_Path("tag", "name"),
 								},
 								Table: parsers.Table{
-									Value: "tag",
+									Value:      "tag",
-									SelectItem: parsers.SelectItem{
+									SelectItem: testutils.SelectItem_Path("c", "tags"),
-										Path: []string{"c", "tags"},
+									IsInSelect: true,
-									},
 								},
 							},
 						},
@@ -82,10 +80,10 @@ func Test_Parse_SubQuery(t *testing.T) {
 			WHERE hasTags`,
 			parsers.SelectStmt{
 				SelectItems: []parsers.SelectItem{
-					{Path: []string{"c", "id"}},
+					testutils.SelectItem_Path("c", "id"),
 				},
 				Table: parsers.Table{
-					Value: "c",
+					SelectItem: testutils.SelectItem_Path("c"),
 				},
 				JoinItems: []parsers.JoinItem{
 					{
@@ -100,13 +98,12 @@ func Test_Parse_SubQuery(t *testing.T) {
 										Type:       parsers.SelectItemTypeSubQuery,
 										Value: parsers.SelectStmt{
 											SelectItems: []parsers.SelectItem{
-												{Path: []string{"tag", "name"}},
+												testutils.SelectItem_Path("tag", "name"),
 											},
 											Table: parsers.Table{
-												Value: "tag",
+												Value:      "tag",
-												SelectItem: parsers.SelectItem{
+												SelectItem: testutils.SelectItem_Path("c", "tags"),
-													Path: []string{"c", "tags"},
+												IsInSelect: true,
-												},
 											},
 											Exists: true,
 										},

parsers/nosql/type_checking_functions_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/pikami/cosmium/parsers"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Execute_TypeCheckingFunctions(t *testing.T) {
@@ -27,7 +28,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -63,7 +64,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -99,7 +100,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -135,7 +136,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -171,7 +172,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -207,7 +208,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -243,7 +244,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -279,7 +280,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -315,7 +316,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -351,7 +352,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{

parsers/nosql/were_test.go

@@ -19,7 +19,7 @@ func Test_Parse_Were(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "id"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.ComparisonExpression{
 					Operation: "=",
 					Left:      parsers.SelectItem{Path: []string{"c", "isCool"}},
@@ -42,7 +42,7 @@ func Test_Parse_Were(t *testing.T) {
 					{Path: []string{"c", "_rid"}},
 					{Path: []string{"c", "_ts"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.LogicalExpression{
 					Operation: parsers.LogicalExpressionTypeOr,
 					Expressions: []interface{}{
@@ -72,7 +72,7 @@ func Test_Parse_Were(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "id"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.LogicalExpression{
 					Operation: parsers.LogicalExpressionTypeAnd,
 					Expressions: []interface{}{
@@ -114,7 +114,7 @@ func Test_Parse_Were(t *testing.T) {
 			AND c.param=@param_id1`,
 			parsers.SelectStmt{
 				SelectItems: []parsers.SelectItem{{Path: []string{"c", "id"}, Alias: ""}},
-				Table:       parsers.Table{Value: "c"},
+				Table:       parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.LogicalExpression{
 					Expressions: []interface{}{
 						parsers.ComparisonExpression{

query_executors/memory_executor/aggregate_functions_test.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/pikami/cosmium/parsers"
 	memoryexecutor "github.com/pikami/cosmium/query_executors/memory_executor"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Execute_AggregateFunctions(t *testing.T) {
@@ -38,7 +39,7 @@ func Test_Execute_AggregateFunctions(t *testing.T) {
 				GroupBy: []parsers.SelectItem{
 					{Path: []string{"c", "key"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -67,7 +68,7 @@ func Test_Execute_AggregateFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -99,7 +100,7 @@ func Test_Execute_AggregateFunctions(t *testing.T) {
 				GroupBy: []parsers.SelectItem{
 					{Path: []string{"c", "key"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -132,7 +133,7 @@ func Test_Execute_AggregateFunctions(t *testing.T) {
 				GroupBy: []parsers.SelectItem{
 					{Path: []string{"c", "key"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -165,7 +166,7 @@ func Test_Execute_AggregateFunctions(t *testing.T) {
 				GroupBy: []parsers.SelectItem{
 					{Path: []string{"c", "key"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -198,7 +199,7 @@ func Test_Execute_AggregateFunctions(t *testing.T) {
 				GroupBy: []parsers.SelectItem{
 					{Path: []string{"c", "key"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{

query_executors/memory_executor/array_functions.go

@@ -220,7 +220,7 @@ func (r rowContext) partialMatch(item interface{}, exprToSearch interface{}) boo
 	}
 
 	for _, key := range exprValue.MapKeys() {
-		if itemValue.MapIndex(key).Interface() != exprValue.MapIndex(key).Interface() {
+		if !reflect.DeepEqual(itemValue.MapIndex(key).Interface(), exprValue.MapIndex(key).Interface()) {
 			return false
 		}
 	}

query_executors/memory_executor/array_functions_test.go

@@ -42,7 +42,7 @@ func Test_Execute_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -59,10 +59,11 @@ func Test_Execute_ArrayFunctions(t *testing.T) {
 			parsers.SelectStmt{
 				Parameters: map[string]interface{}{
 					"@categories":                []interface{}{"coats", "jackets", "sweatshirts"},
-					"@objectArray":               []interface{}{map[string]interface{}{"category": "shirts", "color": "blue"}},
+					"@objectArray":               []interface{}{map[string]interface{}{"category": "shirts", "color": "blue", "nestedObject": map[string]interface{}{"size": "M"}}},
-					"@fullMatchObject":           map[string]interface{}{"category": "shirts", "color": "blue"},
+					"@fullMatchObject":           map[string]interface{}{"category": "shirts", "color": "blue", "nestedObject": map[string]interface{}{"size": "M"}},
 					"@partialMatchObject":        map[string]interface{}{"category": "shirts"},
 					"@missingPartialMatchObject": map[string]interface{}{"category": "shorts", "color": "blue"},
+					"@nestedPartialMatchObject":  map[string]interface{}{"nestedObject": map[string]interface{}{"size": "M"}},
 				},
 				SelectItems: []parsers.SelectItem{
 					{
@@ -133,17 +134,30 @@ func Test_Execute_ArrayFunctions(t *testing.T) {
 							},
 						},
 					},
+					{
+						Alias: "ContainsNestedPartialMatchObject",
+						Type:  parsers.SelectItemTypeFunctionCall,
+						Value: parsers.FunctionCall{
+							Type: parsers.FunctionCallArrayContains,
+							Arguments: []interface{}{
+								testutils.SelectItem_Constant_Parameter("@objectArray"),
+								testutils.SelectItem_Constant_Parameter("@nestedPartialMatchObject"),
+								testutils.SelectItem_Constant_Bool(true),
+							},
+						},
+					},
 				},
 			},
 			[]memoryexecutor.RowType{map[string]interface{}{"id": "123"}},
 			[]memoryexecutor.RowType{
 				map[string]interface{}{
-					"ContainsItem":               true,
+					"ContainsItem":                     true,
-					"MissingItem":                false,
+					"MissingItem":                      false,
-					"ContainsFullMatchObject":    true,
+					"ContainsFullMatchObject":          true,
-					"MissingFullMatchObject":     false,
+					"MissingFullMatchObject":           false,
-					"ContainsPartialMatchObject": true,
+					"ContainsPartialMatchObject":       true,
-					"MissingPartialMatchObject":  false,
+					"MissingPartialMatchObject":        false,
+					"ContainsNestedPartialMatchObject": true,
 				},
 			},
 		)
@@ -356,7 +370,7 @@ func Test_Execute_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -392,7 +406,7 @@ func Test_Execute_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -430,7 +444,7 @@ func Test_Execute_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -468,7 +482,7 @@ func Test_Execute_ArrayFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{

query_executors/memory_executor/join_test.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/pikami/cosmium/parsers"
 	memoryexecutor "github.com/pikami/cosmium/query_executors/memory_executor"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Execute_Joins(t *testing.T) {
@@ -33,7 +34,7 @@ func Test_Execute_Joins(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"cc", "name"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				JoinItems: []parsers.JoinItem{
 					{
 						Table: parsers.Table{
@@ -62,7 +63,7 @@ func Test_Execute_Joins(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"cc"}, IsTopLevel: true},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				JoinItems: []parsers.JoinItem{
 					{
 						Table: parsers.Table{

query_executors/memory_executor/math_functions_test.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/pikami/cosmium/parsers"
 	memoryexecutor "github.com/pikami/cosmium/query_executors/memory_executor"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Execute_MathFunctions(t *testing.T) {
@@ -261,7 +262,7 @@ func testMathFunctionExecute(
 					},
 				},
 			},
-			Table: parsers.Table{Value: "c"},
+			Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 		},
 		data,
 		expectedData,

query_executors/memory_executor/memory_executor.go

@@ -60,6 +60,15 @@ func ExecuteQuery(query parsers.SelectStmt, documents []RowType) []RowType {
 		projectedDocuments = deduplicate(projectedDocuments)
 	}
 
+	// Apply offset
+	if query.Offset > 0 {
+		if query.Offset < len(projectedDocuments) {
+			projectedDocuments = projectedDocuments[query.Offset:]
+		} else {
+			projectedDocuments = []RowType{}
+		}
+	}
+
 	// Apply result limit
 	if query.Count > 0 && len(projectedDocuments) > query.Count {
 		projectedDocuments = projectedDocuments[:query.Count]
@@ -80,10 +89,15 @@ func resolveFrom(query parsers.SelectStmt, doc RowType) []rowContext {
 			initialTableName = query.Table.Value
 		}
 
+		if initialTableName == "" {
+			initialTableName = resolveDestinationColumnName(query.Table.SelectItem, 0, query.Parameters)
+		}
+
 		initialRow = rowContext{
 			parameters: query.Parameters,
 			tables: map[string]RowType{
 				initialTableName: doc,
+				"$root":          doc,
 			},
 		}
 	}
@@ -93,15 +107,33 @@ func resolveFrom(query parsers.SelectStmt, doc RowType) []rowContext {
 		if destinationTableName == "" {
 			destinationTableName = query.Table.Value
 		}
-
+		if destinationTableName == "" {
-		selectValue := initialRow.parseArray(query.Table.SelectItem)
+			destinationTableName = resolveDestinationColumnName(query.Table.SelectItem, 0, initialRow.parameters)
-		rowContexts := make([]rowContext, len(selectValue))
-		for i, newRowData := range selectValue {
-			rowContexts[i].parameters = initialRow.parameters
-			rowContexts[i].tables = copyMap(initialRow.tables)
-			rowContexts[i].tables[destinationTableName] = newRowData
 		}
-		return rowContexts
+
+		if query.Table.IsInSelect || query.Table.SelectItem.Type == parsers.SelectItemTypeSubQuery {
+			selectValue := initialRow.parseArray(query.Table.SelectItem)
+			rowContexts := make([]rowContext, len(selectValue))
+			for i, newRowData := range selectValue {
+				rowContexts[i].parameters = initialRow.parameters
+				rowContexts[i].tables = copyMap(initialRow.tables)
+				rowContexts[i].tables[destinationTableName] = newRowData
+			}
+			return rowContexts
+		}
+
+		if len(query.Table.SelectItem.Path) > 0 {
+			sourceTableName := query.Table.SelectItem.Path[0]
+			sourceTableData := initialRow.tables[sourceTableName]
+			if sourceTableData == nil {
+				// When source table is not found, assume it's root document
+				initialRow.tables[sourceTableName] = initialRow.tables["$root"]
+			}
+		}
+
+		newRowData := initialRow.resolveSelectItem(query.Table.SelectItem)
+		initialRow.tables[destinationTableName] = newRowData
+		return []rowContext{initialRow}
 	}
 
 	return []rowContext{initialRow}
@@ -310,18 +342,7 @@ func (r rowContext) applyProjection(selectItems []parsers.SelectItem) RowType {
 	// Construct a new row based on the selected columns
 	row := make(map[string]interface{})
 	for index, selectItem := range selectItems {
-		destinationName := selectItem.Alias
+		destinationName := resolveDestinationColumnName(selectItem, index, r.parameters)
-		if destinationName == "" {
-			if len(selectItem.Path) > 0 {
-				destinationName = selectItem.Path[len(selectItem.Path)-1]
-			} else {
-				destinationName = fmt.Sprintf("$%d", index+1)
-			}
-
-			if destinationName[0] == '@' {
-				destinationName = r.parameters[destinationName].(string)
-			}
-		}
 
 		row[destinationName] = r.resolveSelectItem(selectItem)
 	}
@@ -329,6 +350,23 @@ func (r rowContext) applyProjection(selectItems []parsers.SelectItem) RowType {
 	return row
 }
 
+func resolveDestinationColumnName(selectItem parsers.SelectItem, itemIndex int, queryParameters map[string]interface{}) string {
+	if selectItem.Alias != "" {
+		return selectItem.Alias
+	}
+
+	destinationName := fmt.Sprintf("$%d", itemIndex+1)
+	if len(selectItem.Path) > 0 {
+		destinationName = selectItem.Path[len(selectItem.Path)-1]
+	}
+
+	if destinationName[0] == '@' {
+		destinationName = queryParameters[destinationName].(string)
+	}
+
+	return destinationName
+}
+
 func (r rowContext) resolveSelectItem(selectItem parsers.SelectItem) interface{} {
 	if selectItem.Type == parsers.SelectItemTypeArray {
 		return r.selectItem_SelectItemTypeArray(selectItem)

query_executors/memory_executor/misc_test.go

@@ -50,7 +50,7 @@ func Test_Execute(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "pk"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				OrderExpressions: []parsers.OrderExpression{
 					{
 						SelectItem: parsers.SelectItem{Path: []string{"c", "pk"}},
@@ -79,7 +79,7 @@ func Test_Execute(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "pk"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				GroupBy: []parsers.SelectItem{
 					{Path: []string{"c", "pk"}},
 				},
@@ -102,7 +102,7 @@ func Test_Execute(t *testing.T) {
 						Type: parsers.SelectItemTypeField,
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.SelectItem{
 					Type: parsers.SelectItemTypeFunctionCall,
 					Value: parsers.FunctionCall{
@@ -137,10 +137,9 @@ func Test_Execute(t *testing.T) {
 					},
 				},
 				Table: parsers.Table{
-					Value: "c",
+					Value:      "c",
-					SelectItem: parsers.SelectItem{
+					SelectItem: testutils.SelectItem_Path("c", "tags"),
-						Path: []string{"c", "tags"},
+					IsInSelect: true,
-					},
 				},
 			},
 			mockData,

query_executors/memory_executor/select_test.go

@@ -5,14 +5,15 @@ import (
 
 	"github.com/pikami/cosmium/parsers"
 	memoryexecutor "github.com/pikami/cosmium/query_executors/memory_executor"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Execute_Select(t *testing.T) {
 	mockData := []memoryexecutor.RowType{
-		map[string]interface{}{"id": "12345", "pk": 123, "_self": "self1", "_rid": "rid1", "_ts": 123456, "isCool": false},
+		map[string]interface{}{"id": "12345", "pk": 123, "_self": "self1", "_rid": "rid1", "_ts": 123456, "isCool": false, "order": 1},
-		map[string]interface{}{"id": "67890", "pk": 456, "_self": "self2", "_rid": "rid2", "_ts": 789012, "isCool": true},
+		map[string]interface{}{"id": "67890", "pk": 456, "_self": "self2", "_rid": "rid2", "_ts": 789012, "isCool": true, "order": 2},
-		map[string]interface{}{"id": "456", "pk": 456, "_self": "self2", "_rid": "rid2", "_ts": 789012, "isCool": true},
+		map[string]interface{}{"id": "456", "pk": 456, "_self": "self2", "_rid": "rid2", "_ts": 789012, "isCool": true, "order": 3},
-		map[string]interface{}{"id": "123", "pk": 456, "_self": "self2", "_rid": "rid2", "_ts": 789012, "isCool": true},
+		map[string]interface{}{"id": "123", "pk": 456, "_self": "self2", "_rid": "rid2", "_ts": 789012, "isCool": true, "order": 4},
 	}
 
 	t.Run("Should execute simple SELECT", func(t *testing.T) {
@@ -23,7 +24,7 @@ func Test_Execute_Select(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "pk"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -43,7 +44,7 @@ func Test_Execute_Select(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "@param"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Parameters: map[string]interface{}{
 					"@param": "pk",
 				},
@@ -65,7 +66,7 @@ func Test_Execute_Select(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "pk"}},
 				},
-				Table:    parsers.Table{Value: "c"},
+				Table:    parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Distinct: true,
 			},
 			mockData,
@@ -84,7 +85,7 @@ func Test_Execute_Select(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "pk"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Count: 1,
 			},
 			mockData,
@@ -102,20 +103,20 @@ func Test_Execute_Select(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "pk"}},
 				},
-				Table:  parsers.Table{Value: "c"},
+				Table:  parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Count:  2,
 				Offset: 1,
 				OrderExpressions: []parsers.OrderExpression{
 					{
-						SelectItem: parsers.SelectItem{Path: []string{"c", "id"}},
+						SelectItem: parsers.SelectItem{Path: []string{"c", "order"}},
 						Direction:  parsers.OrderDirectionDesc,
 					},
 				},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
-				map[string]interface{}{"id": "67890", "pk": 456},
 				map[string]interface{}{"id": "456", "pk": 456},
+				map[string]interface{}{"id": "67890", "pk": 456},
 			},
 		)
 	})
@@ -127,7 +128,7 @@ func Test_Execute_Select(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "id"}, IsTopLevel: true},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -146,7 +147,7 @@ func Test_Execute_Select(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c"}, IsTopLevel: true},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			mockData,
@@ -167,7 +168,7 @@ func Test_Execute_Select(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -193,7 +194,7 @@ func Test_Execute_Select(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{

query_executors/memory_executor/string_functions_test.go

@@ -40,7 +40,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -76,7 +76,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -112,7 +112,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -148,7 +148,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -184,7 +184,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -220,7 +220,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -256,7 +256,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -290,7 +290,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -325,7 +325,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -359,7 +359,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -393,7 +393,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -429,7 +429,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -464,7 +464,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -498,7 +498,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -533,7 +533,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -567,7 +567,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -603,7 +603,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -637,7 +637,7 @@ func Test_Execute_StringFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{

query_executors/memory_executor/subquery_test.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/pikami/cosmium/parsers"
 	memoryexecutor "github.com/pikami/cosmium/query_executors/memory_executor"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Execute_SubQuery(t *testing.T) {
@@ -41,7 +42,7 @@ func Test_Execute_SubQuery(t *testing.T) {
 						Alias: "c",
 						Type:  parsers.SelectItemTypeSubQuery,
 						Value: parsers.SelectStmt{
-							Table: parsers.Table{Value: "cc"},
+							Table: parsers.Table{SelectItem: testutils.SelectItem_Path("cc")},
 							SelectItems: []parsers.SelectItem{
 								{Path: []string{"cc", "info"}, IsTopLevel: true},
 							},
@@ -66,9 +67,7 @@ func Test_Execute_SubQuery(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"cc", "name"}},
 				},
-				Table: parsers.Table{
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
-					Value: "c",
-				},
 				JoinItems: []parsers.JoinItem{
 					{
 						Table: parsers.Table{
@@ -79,13 +78,12 @@ func Test_Execute_SubQuery(t *testing.T) {
 							Type:  parsers.SelectItemTypeSubQuery,
 							Value: parsers.SelectStmt{
 								SelectItems: []parsers.SelectItem{
-									{Path: []string{"tag", "name"}},
+									testutils.SelectItem_Path("tag", "name"),
 								},
 								Table: parsers.Table{
-									Value: "tag",
+									Value:      "tag",
-									SelectItem: parsers.SelectItem{
+									SelectItem: testutils.SelectItem_Path("c", "tags"),
-										Path: []string{"c", "tags"},
+									IsInSelect: true,
-									},
 								},
 							},
 						},
@@ -107,10 +105,10 @@ func Test_Execute_SubQuery(t *testing.T) {
 			t,
 			parsers.SelectStmt{
 				SelectItems: []parsers.SelectItem{
-					{Path: []string{"c", "id"}},
+					testutils.SelectItem_Path("c", "id"),
 				},
 				Table: parsers.Table{
-					Value: "c",
+					SelectItem: testutils.SelectItem_Path("c"),
 				},
 				JoinItems: []parsers.JoinItem{
 					{
@@ -125,13 +123,12 @@ func Test_Execute_SubQuery(t *testing.T) {
 										Type:       parsers.SelectItemTypeSubQuery,
 										Value: parsers.SelectStmt{
 											SelectItems: []parsers.SelectItem{
-												{Path: []string{"tag", "name"}},
+												testutils.SelectItem_Path("tag", "name"),
 											},
 											Table: parsers.Table{
-												Value: "tag",
+												Value:      "tag",
-												SelectItem: parsers.SelectItem{
+												SelectItem: testutils.SelectItem_Path("c", "tags"),
-													Path: []string{"c", "tags"},
+												IsInSelect: true,
-												},
 											},
 											Exists: true,
 										},

query_executors/memory_executor/type_checking_functions_test.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/pikami/cosmium/parsers"
 	memoryexecutor "github.com/pikami/cosmium/query_executors/memory_executor"
+	testutils "github.com/pikami/cosmium/test_utils"
 )
 
 func Test_Execute_TypeCheckingFunctions(t *testing.T) {
@@ -40,7 +41,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -76,7 +77,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -112,7 +113,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -148,7 +149,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -184,7 +185,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -220,7 +221,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -256,7 +257,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -292,7 +293,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -328,7 +329,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{
@@ -364,7 +365,7 @@ func Test_Execute_TypeCheckingFunctions(t *testing.T) {
 						},
 					},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 			},
 			mockData,
 			[]memoryexecutor.RowType{

query_executors/memory_executor/were_test.go

@@ -23,7 +23,7 @@ func Test_Execute_Where(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "id"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.ComparisonExpression{
 					Operation: "=",
 					Left:      parsers.SelectItem{Path: []string{"c", "isCool"}},
@@ -46,7 +46,7 @@ func Test_Execute_Where(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "id"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.ComparisonExpression{
 					Operation: "=",
 					Left:      parsers.SelectItem{Path: []string{"c", "id"}},
@@ -71,7 +71,7 @@ func Test_Execute_Where(t *testing.T) {
 					{Path: []string{"c", "id"}},
 					{Path: []string{"c", "_self"}, Alias: "self"},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.LogicalExpression{
 					Operation: parsers.LogicalExpressionTypeAnd,
 					Expressions: []interface{}{
@@ -102,7 +102,7 @@ func Test_Execute_Where(t *testing.T) {
 				SelectItems: []parsers.SelectItem{
 					{Path: []string{"c", "id"}},
 				},
-				Table: parsers.Table{Value: "c"},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
 				Filters: parsers.LogicalExpression{
 					Operation: parsers.LogicalExpressionTypeAnd,
 					Expressions: []interface{}{

sharedlibrary/collections.go

@@ -3,6 +3,7 @@ package main
 import "C"
 import (
 	"encoding/json"
+	"strings"
 
 	repositorymodels "github.com/pikami/cosmium/internal/repository_models"
 )
@@ -20,7 +21,7 @@ func CreateCollection(serverName *C.char, databaseId *C.char, collectionJson *C.
 	}
 
 	var collection repositorymodels.Collection
-	err := json.Unmarshal([]byte(collectionStr), &collection)
+	err := json.NewDecoder(strings.NewReader(collectionStr)).Decode(&collection)
 	if err != nil {
 		return ResponseFailedToParseRequest
 	}

sharedlibrary/databases.go

@@ -3,6 +3,7 @@ package main
 import "C"
 import (
 	"encoding/json"
+	"strings"
 
 	repositorymodels "github.com/pikami/cosmium/internal/repository_models"
 )
@@ -19,7 +20,7 @@ func CreateDatabase(serverName *C.char, databaseJson *C.char) int {
 	}
 
 	var database repositorymodels.Database
-	err := json.Unmarshal([]byte(databaseStr), &database)
+	err := json.NewDecoder(strings.NewReader(databaseStr)).Decode(&database)
 	if err != nil {
 		return ResponseFailedToParseRequest
 	}

sharedlibrary/documents.go

@@ -3,6 +3,7 @@ package main
 import "C"
 import (
 	"encoding/json"
+	"strings"
 
 	repositorymodels "github.com/pikami/cosmium/internal/repository_models"
 )
@@ -21,7 +22,7 @@ func CreateDocument(serverName *C.char, databaseId *C.char, collectionId *C.char
 	}
 
 	var document repositorymodels.Document
-	err := json.Unmarshal([]byte(documentStr), &document)
+	err := json.NewDecoder(strings.NewReader(documentStr)).Decode(&document)
 	if err != nil {
 		return ResponseFailedToParseRequest
 	}

sharedlibrary/shared.go

@@ -13,8 +13,10 @@ type ServerInstance struct {
 	repository *repositories.DataRepository
 }
 
-var serverInstances map[string]*ServerInstance
+var (
-var mutex sync.Mutex
+	serverInstances = make(map[string]*ServerInstance)
+	mutex           = sync.Mutex{}
+)
 
 const (
 	ResponseSuccess = 0
@@ -25,6 +27,7 @@ const (
 	ResponseFailedToParseRequest        = 103
 	ResponseServerInstanceAlreadyExists = 104
 	ResponseServerInstanceNotFound      = 105
+	ResponseFailedToStartServer         = 106
 
 	ResponseRepositoryNotFound   = 200
 	ResponseRepositoryConflict   = 201
@@ -35,10 +38,6 @@ func getInstance(serverName string) (*ServerInstance, bool) {
 	mutex.Lock()
 	defer mutex.Unlock()
 
-	if serverInstances == nil {
-		serverInstances = make(map[string]*ServerInstance)
-	}
-
 	var ok bool
 	var serverInstance *ServerInstance
 	if serverInstance, ok = serverInstances[serverName]; !ok {
@@ -52,10 +51,6 @@ func addInstance(serverName string, serverInstance *ServerInstance) {
 	mutex.Lock()
 	defer mutex.Unlock()
 
-	if serverInstances == nil {
-		serverInstances = make(map[string]*ServerInstance)
-	}
-
 	serverInstances[serverName] = serverInstance
 }
 
@@ -63,10 +58,6 @@ func removeInstance(serverName string) {
 	mutex.Lock()
 	defer mutex.Unlock()
 
-	if serverInstances == nil {
-		return
-	}
-
 	delete(serverInstances, serverName)
 }
 

sharedlibrary/sharedlibrary.go

@@ -1,8 +1,13 @@
 package main
 
+/*
+#include <stdlib.h>
+*/
 import "C"
 import (
 	"encoding/json"
+	"strings"
+	"unsafe"
 
 	"github.com/pikami/cosmium/api"
 	"github.com/pikami/cosmium/api/config"
@@ -11,21 +16,21 @@ import (
 
 //export CreateServerInstance
 func CreateServerInstance(serverName *C.char, configurationJSON *C.char) int {
-	configStr := C.GoString(configurationJSON)
 	serverNameStr := C.GoString(serverName)
+	configStr := C.GoString(configurationJSON)
 
 	if _, ok := getInstance(serverNameStr); ok {
 		return ResponseServerInstanceAlreadyExists
 	}
 
 	var configuration config.ServerConfig
-	err := json.Unmarshal([]byte(configStr), &configuration)
+	err := json.NewDecoder(strings.NewReader(configStr)).Decode(&configuration)
 	if err != nil {
 		return ResponseFailedToParseConfiguration
 	}
 
-	configuration.PopulateCalculatedFields()
 	configuration.ApplyDefaultsToEmptyFields()
+	configuration.PopulateCalculatedFields()
 
 	repository := repositories.NewDataRepository(repositories.RepositoryOptions{
 		InitialDataFilePath: configuration.InitialDataFilePath,
@@ -33,7 +38,10 @@ func CreateServerInstance(serverName *C.char, configurationJSON *C.char) int {
 	})
 
 	server := api.NewApiServer(repository, configuration)
-	server.Start()
+	err = server.Start()
+	if err != nil {
+		return ResponseFailedToStartServer
+	}
 
 	addInstance(serverNameStr, &ServerInstance{
 		server:     server,
@@ -87,4 +95,9 @@ func LoadServerInstanceState(serverName *C.char, stateJSON *C.char) int {
 	return ResponseServerInstanceNotFound
 }
 
+//export FreeMemory
+func FreeMemory(ptr *C.char) {
+	C.free(unsafe.Pointer(ptr))
+}
+
 func main() {}

test_utils/parser_model_gen.go

@@ -51,3 +51,9 @@ func SelectItem_Constant_Parameter(name string) parsers.SelectItem {
 		},
 	}
 }
+
+func SelectItem_Path(path ...string) parsers.SelectItem {
+	return parsers.SelectItem{
+		Path: path,
+	}
+}