Add support for subqueries

parsers/nosql/misc_test.go

@@ -122,4 +122,25 @@ func Test_Parse(t *testing.T) {
 			},
 		)
 	})
+
+	t.Run("Should parse IN selector", func(t *testing.T) {
+		testQueryParse(
+			t,
+			`SELECT c.id FROM c IN c.tags`,
+			parsers.SelectStmt{
+				SelectItems: []parsers.SelectItem{
+					{
+						Path: []string{"c", "id"},
+						Type: parsers.SelectItemTypeField,
+					},
+				},
+				Table: parsers.Table{
+					Value: "c",
+					SelectItem: parsers.SelectItem{
+						Path: []string{"c", "tags"},
+					},
+				},
+			},
+		)
+	})
 }

parsers/nosql/nosql.peg

@@ -4,16 +4,19 @@ package nosql
 import "github.com/pikami/cosmium/parsers"
 
 func makeSelectStmt(
-	columns, table, joinItems,
+	columns, fromClause, joinItems,
 	whereClause interface{}, distinctClause interface{},
 	count interface{}, groupByClause interface{}, orderList interface{},
 	offsetClause interface{},
 ) (parsers.SelectStmt, error) {
 	selectStmt := parsers.SelectStmt{
 		SelectItems: columns.([]parsers.SelectItem),
-		Table:       table.(parsers.Table),
 	}
 
+    if fromTable, ok := fromClause.(parsers.Table); ok {
+        selectStmt.Table = fromTable
+    }
+
     if joinItemsArray, ok := joinItems.([]interface{}); ok && len(joinItemsArray) > 0 {
 		selectStmt.JoinItems = make([]parsers.JoinItem, len(joinItemsArray))
 		for i, joinItem := range joinItemsArray {
@@ -56,10 +59,18 @@ func makeSelectStmt(
 }
 
 func makeJoin(table interface{}, column interface{}) (parsers.JoinItem, error) {
-    return parsers.JoinItem{
-        Table:      table.(parsers.Table),
-        SelectItem: column.(parsers.SelectItem),
-    }, nil
+	joinItem := parsers.JoinItem{}
+
+	if selectItem, isSelectItem := column.(parsers.SelectItem); isSelectItem {
+		joinItem.SelectItem = selectItem
+		joinItem.Table.Value = selectItem.Alias
+	}
+
+	if tableTyped, isTable := table.(parsers.Table); isTable {
+		joinItem.Table = tableTyped
+	}
+
+	return joinItem, nil
 }
 
 func makeSelectItem(name interface{}, path interface{}, selectItemType parsers.SelectItemType) (parsers.SelectItem, error) {
@@ -177,13 +188,13 @@ SelectStmt <- Select ws
     distinctClause:DistinctClause? ws
     topClause:TopClause? ws
     columns:Selection ws
-    From ws table:TableName ws
-    joinClauses:JoinClause* ws
+    fromClause:FromClause? ws
+    joinClauses:(ws join:JoinClause { return join, nil })* ws
     whereClause:(ws Where ws condition:Condition { return condition, nil })?
     groupByClause:(ws GroupBy ws columns:ColumnList { return columns, nil })?
-    orderByClause:OrderByClause?
-    offsetClause:OffsetClause? {
-    return makeSelectStmt(columns, table, joinClauses, whereClause,
+    orderByClause:(ws order:OrderByClause { return order, nil })?
+    offsetClause:(ws offset:OffsetClause { return offset, nil })? {
+    return makeSelectStmt(columns, fromClause, joinClauses, whereClause,
         distinctClause, topClause, groupByClause, orderByClause, offsetClause)
 }
 
@@ -193,8 +204,49 @@ TopClause <- Top ws count:Integer {
     return count, nil
 }
 
+FromClause <- From ws table:TableName selectItem:(ws "IN"i ws column:SelectItem { return column, nil })? {
+    tableTyped := table.(parsers.Table)
+
+    if selectItem != nil {
+	    tableTyped.SelectItem = selectItem.(parsers.SelectItem)
+	}
+
+	return tableTyped, nil
+} / From ws subQuery:SubQuerySelectItem {
+    subQueryTyped := subQuery.(parsers.SelectItem)
+	table := parsers.Table{
+		Value: subQueryTyped.Alias,
+		SelectItem: subQueryTyped,
+	}
+	return table, nil
+}
+
+SubQuery <- exists:(exists:Exists ws { return exists, nil })? "(" ws selectStmt:SelectStmt ws ")" {
+    if selectStatement, isGoodValue := selectStmt.(parsers.SelectStmt); isGoodValue {
+        selectStatement.Exists = exists != nil
+        return selectStatement, nil
+    }
+
+    return selectStmt, nil
+}
+
+SubQuerySelectItem <- subQuery:SubQuery asClause:(ws alias:AsClause { return alias, nil })? {
+    selectItem := parsers.SelectItem{
+        Type: parsers.SelectItemTypeSubQuery,
+        Value: subQuery,
+    }
+
+    if tableName, isString := asClause.(string); isString {
+        selectItem.Alias = tableName
+    }
+
+    return selectItem, nil
+}
+
 JoinClause <- Join ws table:TableName ws "IN"i 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 {
@@ -241,7 +293,7 @@ SelectProperty <- name:Identifier path:(DotFieldAccess / ArrayFieldAccess)* {
     return makeSelectItem(name, path, parsers.SelectItemTypeField)
 }
 
-SelectItem <- selectItem:(Literal / FunctionCall / SelectArray / SelectObject / SelectProperty) asClause:AsClause? {
+SelectItem <- selectItem:(SubQuerySelectItem / Literal / FunctionCall / SelectArray / SelectObject / SelectProperty) asClause:AsClause? {
     var itemResult parsers.SelectItem
     switch typedValue := selectItem.(type) {
     case parsers.SelectItem:
@@ -322,11 +374,13 @@ From <- "FROM"i
 
 Join <- "JOIN"i
 
+Exists <- "EXISTS"i
+
 Where <- "WHERE"i
 
 And <- "AND"i
 
-Or <- "OR"i
+Or <- "OR"i wss
 
 GroupBy <- "GROUP"i ws "BY"i
 
@@ -677,4 +731,6 @@ non_escape_character <- !(escape_character) char:.
 
 ws <- [ \t\n\r]*
 
+wss <- [ \t\n\r]+
+
 EOF <- !.

parsers/nosql/subquery_test.go

@@ -0,0 +1,125 @@
+package nosql_test
+
+import (
+	"testing"
+
+	"github.com/pikami/cosmium/parsers"
+)
+
+func Test_Parse_SubQuery(t *testing.T) {
+
+	t.Run("Should parse FROM subquery", func(t *testing.T) {
+		testQueryParse(
+			t,
+			`SELECT c.id FROM (SELECT VALUE cc["info"] FROM cc) AS c`,
+			parsers.SelectStmt{
+				SelectItems: []parsers.SelectItem{
+					{Path: []string{"c", "id"}},
+				},
+				Table: parsers.Table{
+					Value: "c",
+					SelectItem: parsers.SelectItem{
+						Alias: "c",
+						Type:  parsers.SelectItemTypeSubQuery,
+						Value: parsers.SelectStmt{
+							Table: parsers.Table{Value: "cc"},
+							SelectItems: []parsers.SelectItem{
+								{Path: []string{"cc", "info"}, IsTopLevel: true},
+							},
+						},
+					},
+				},
+			},
+		)
+	})
+
+	t.Run("Should parse JOIN subquery", func(t *testing.T) {
+		testQueryParse(
+			t,
+			`SELECT c.id, cc.name FROM c JOIN (SELECT tag.name FROM tag IN c.tags) AS cc`,
+			parsers.SelectStmt{
+				SelectItems: []parsers.SelectItem{
+					{Path: []string{"c", "id"}},
+					{Path: []string{"cc", "name"}},
+				},
+				Table: parsers.Table{
+					Value: "c",
+				},
+				JoinItems: []parsers.JoinItem{
+					{
+						Table: parsers.Table{
+							Value: "cc",
+						},
+						SelectItem: parsers.SelectItem{
+							Alias: "cc",
+							Type:  parsers.SelectItemTypeSubQuery,
+							Value: parsers.SelectStmt{
+								SelectItems: []parsers.SelectItem{
+									{Path: []string{"tag", "name"}},
+								},
+								Table: parsers.Table{
+									Value: "tag",
+									SelectItem: parsers.SelectItem{
+										Path: []string{"c", "tags"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		)
+	})
+
+	t.Run("Should parse JOIN EXISTS subquery", func(t *testing.T) {
+		testQueryParse(
+			t,
+			`SELECT c.id
+			FROM c
+			JOIN (
+				SELECT VALUE EXISTS(SELECT tag.name FROM tag IN c.tags)
+			) AS hasTags
+			WHERE hasTags`,
+			parsers.SelectStmt{
+				SelectItems: []parsers.SelectItem{
+					{Path: []string{"c", "id"}},
+				},
+				Table: parsers.Table{
+					Value: "c",
+				},
+				JoinItems: []parsers.JoinItem{
+					{
+						Table: parsers.Table{Value: "hasTags"},
+						SelectItem: parsers.SelectItem{
+							Alias: "hasTags",
+							Type:  parsers.SelectItemTypeSubQuery,
+							Value: parsers.SelectStmt{
+								SelectItems: []parsers.SelectItem{
+									{
+										IsTopLevel: true,
+										Type:       parsers.SelectItemTypeSubQuery,
+										Value: parsers.SelectStmt{
+											SelectItems: []parsers.SelectItem{
+												{Path: []string{"tag", "name"}},
+											},
+											Table: parsers.Table{
+												Value: "tag",
+												SelectItem: parsers.SelectItem{
+													Path: []string{"c", "tags"},
+												},
+											},
+											Exists: true,
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+				Filters: parsers.SelectItem{
+					Path: []string{"hasTags"},
+				},
+			},
+		)
+	})
+}