Implement IIF function; Fix empty object select

query_executors/memory_executor/common.go

@@ -209,6 +209,9 @@ func (r rowContext) selectItem_SelectItemTypeFunctionCall(functionCall parsers.F
 	case parsers.FunctionCallSetUnion:
 		return r.set_Union(functionCall.Arguments)
 
+	case parsers.FunctionCallIif:
+		return r.misc_Iif(functionCall.Arguments)
+
 	case parsers.FunctionCallMathAbs:
 		return r.math_Abs(functionCall.Arguments)
 	case parsers.FunctionCallMathAcos:

query_executors/memory_executor/misc_functions.go

@@ -16,3 +16,16 @@ func (r rowContext) misc_In(arguments []interface{}) bool {
 
 	return false
 }
+
+func (r rowContext) misc_Iif(arguments []interface{}) interface{} {
+	if len(arguments) != 3 {
+		return nil
+	}
+
+	condition := r.resolveSelectItem(arguments[0].(parsers.SelectItem))
+	if condition != nil && condition == true {
+		return r.resolveSelectItem(arguments[1].(parsers.SelectItem))
+	}
+
+	return r.resolveSelectItem(arguments[2].(parsers.SelectItem))
+}

query_executors/memory_executor/misc_test.go

@@ -210,4 +210,35 @@ func Test_Execute(t *testing.T) {
 			},
 		)
 	})
+
+	t.Run("Should execute function IIF()", func(t *testing.T) {
+		testQueryExecute(
+			t,
+			parsers.SelectStmt{
+				SelectItems: []parsers.SelectItem{
+					testutils.SelectItem_Path("c", "id"),
+					{
+						Alias: "coolness",
+						Type:  parsers.SelectItemTypeFunctionCall,
+						Value: parsers.FunctionCall{
+							Type: parsers.FunctionCallIif,
+							Arguments: []interface{}{
+								testutils.SelectItem_Path("c", "isCool"),
+								testutils.SelectItem_Constant_String("real cool"),
+								testutils.SelectItem_Constant_String("not cool"),
+							},
+						},
+					},
+				},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
+			},
+			mockData,
+			[]memoryexecutor.RowType{
+				map[string]interface{}{"id": "12345", "coolness": "not cool"},
+				map[string]interface{}{"id": "67890", "coolness": "real cool"},
+				map[string]interface{}{"id": "456", "coolness": "real cool"},
+				map[string]interface{}{"id": "123", "coolness": "real cool"},
+			},
+		)
+	})
 }

query_executors/memory_executor/select_test.go

@@ -205,4 +205,27 @@ func Test_Execute_Select(t *testing.T) {
 			},
 		)
 	})
+
+	t.Run("Should execute SELECT empty object", func(t *testing.T) {
+		testQueryExecute(
+			t,
+			parsers.SelectStmt{
+				SelectItems: []parsers.SelectItem{
+					{
+						Alias:       "obj",
+						Type:        parsers.SelectItemTypeObject,
+						SelectItems: []parsers.SelectItem{},
+					},
+				},
+				Table: parsers.Table{SelectItem: testutils.SelectItem_Path("c")},
+			},
+			mockData,
+			[]memoryexecutor.RowType{
+				map[string]interface{}{"obj": map[string]interface{}{}},
+				map[string]interface{}{"obj": map[string]interface{}{}},
+				map[string]interface{}{"obj": map[string]interface{}{}},
+				map[string]interface{}{"obj": map[string]interface{}{}},
+			},
+		)
+	})
 }