port variant type

Author: 俞子丰

chcol.go

@@ -0,0 +1,70 @@
+// Licensed to ClickHouse, Inc. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. ClickHouse, Inc. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package proton
+
+import "github.com/timeplus-io/proton-go-driver/v2/lib/chcol"
+
+// Re-export chcol types/funcs to top level proton package
+
+type (
+	// Variant represents a ClickHouse Variant type that can hold multiple possible types
+	Variant = chcol.Variant
+	// Dynamic is an alias for the Variant type
+	Dynamic = chcol.Dynamic
+	// JSON represents a ClickHouse JSON type that can hold multiple possible types
+	JSON = chcol.JSON
+
+	// JSONSerializer interface allows a struct to be manually converted to an optimized JSON structure instead of relying
+	// on recursive reflection.
+	// Note that the struct must be a pointer in order for the interface to be matched, reflection will be used otherwise.
+	JSONSerializer = chcol.JSONSerializer
+	// JSONDeserializer interface allows a struct to load its data from an optimized JSON structure instead of relying
+	// on recursive reflection to set its fields.
+	JSONDeserializer = chcol.JSONDeserializer
+)
+
+// NewVariant creates a new Variant with the given value
+func NewVariant(v any) Variant {
+	return chcol.NewVariant(v)
+}
+
+// NewVariantWithType creates a new Variant with the given value and ClickHouse type
+func NewVariantWithType(v any, chType string) Variant {
+	return chcol.NewVariantWithType(v, chType)
+}
+
+// NewDynamic creates a new Dynamic with the given value
+func NewDynamic(v any) Dynamic {
+	return chcol.NewDynamic(v)
+}
+
+// NewDynamicWithType creates a new Dynamic with the given value and ClickHouse type
+func NewDynamicWithType(v any, chType string) Dynamic {
+	return chcol.NewDynamicWithType(v, chType)
+}
+
+// NewJSON creates a new empty JSON value
+func NewJSON() *JSON {
+	return chcol.NewJSON()
+}
+
+// ExtractJSONPathAs is a convenience function for asserting a path to a specific type.
+// The underlying value is also extracted from its Dynamic wrapper if present.
+// func ExtractJSONPathAs[T any](o *JSON, path string) (valueAs T, ok bool) {
+// 	return chcol.ExtractJSONPathAs[T](o, path)
+// }

clickhouse_rows.go

@@ -117,7 +117,6 @@ func (r *rows) Close() error {
 			}
 		}
 	}
-	return r.err
 }
 
 func (r *rows) Err() error {

examples/native/variant/variant.go

@@ -0,0 +1,169 @@
+// Licensed to ClickHouse, Inc. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. ClickHouse, Inc. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/timeplus-io/proton-go-driver/v2"
+	proton_tests "github.com/timeplus-io/proton-go-driver/v2/tests"
+)
+
+func VariantExample() error {
+	ctx := context.Background()
+
+	conn, err := proton.Open(&proton.Options{
+		Addr: []string{"127.0.0.1:8463"},
+		Auth: proton.Auth{
+			Database: "default",
+			Username: "default",
+			Password: "",
+		},
+		//Debug:           true,
+		Settings: proton.Settings{
+			"allow_experimental_variant_type": true,
+			"allow_suspicious_variant_types":  true,
+		},
+		DialTimeout:     time.Second,
+		MaxOpenConns:    10,
+		MaxIdleConns:    5,
+		ConnMaxLifetime: time.Hour,
+		Compression: &proton.Compression{
+			Method: proton.CompressionLZ4,
+		},
+	})
+
+	if err != nil {
+		return err
+	}
+
+	if err := proton_tests.CheckMinServerVersion(conn, 2, 9); err != nil {
+		fmt.Print("unsupported timeplus version for Variant type")
+		return err
+	}
+
+	err = conn.Exec(ctx, "DROP STREAM IF EXISTS go_variant_example")
+	if err != nil {
+		return err
+	}
+
+	err = conn.Exec(ctx, `
+		CREATE STREAM go_variant_example (
+		    c variant(bool, int64,  string)
+		) ENGINE = Memory
+	`)
+	if err != nil {
+		return err
+	}
+
+	batch, err := conn.PrepareBatch(ctx, "INSERT INTO go_variant_example (c)")
+	if err != nil {
+		return err
+	}
+
+	if err = batch.Append(true); err != nil {
+		return err
+	}
+
+	if err = batch.Append(int64(42)); err != nil {
+		return err
+	}
+
+	if err = batch.Append("example"); err != nil {
+		return err
+	}
+
+	if err = batch.Append(proton.NewVariant("example variant")); err != nil {
+		return err
+	}
+
+	if err = batch.Append(proton.NewVariantWithType("example variant with specific type", "string")); err != nil {
+		return err
+	}
+
+	if err = batch.Append(nil); err != nil {
+		return err
+	}
+
+	if err = batch.Send(); err != nil {
+		return err
+	}
+
+	// Switch on Go Type
+
+	rows, err := conn.Query(ctx, "SELECT c FROM go_variant_example")
+	if err != nil {
+		return err
+	}
+
+	for i := 0; rows.Next(); i++ {
+		var row proton.Variant
+		err := rows.Scan(&row)
+		if err != nil {
+			return fmt.Errorf("failed to scan row index %d: %w", i, err)
+		}
+
+		switch row.Any().(type) {
+		case bool:
+			fmt.Printf("row at index %d is bool: %v\n", i, row.Any())
+		case int64:
+			fmt.Printf("row at index %d is int64: %v\n", i, row.Any())
+		case string:
+			fmt.Printf("row at index %d is string: %v\n", i, row.Any())
+		case nil:
+			fmt.Printf("row at index %d is NULL\n", i)
+		}
+	}
+
+	// Switch on Timeplus Type
+
+	rows, err = conn.Query(ctx, "SELECT c FROM go_variant_example")
+	if err != nil {
+		return err
+	}
+
+	for i := 0; rows.Next(); i++ {
+		var row proton.Variant
+		err := rows.Scan(&row)
+		if err != nil {
+			return fmt.Errorf("failed to scan row index %d: %w", i, err)
+		}
+
+		switch row.Type() {
+		case "bool":
+			fmt.Printf("row at index %d is bool: %v\n", i, row.Any())
+		case "int64":
+			fmt.Printf("row at index %d is int64: %v\n", i, row.Any())
+		case "string":
+			fmt.Printf("row at index %d is string: %v\n", i, row.Any())
+		case "":
+			fmt.Printf("row at index %d is nil\n", i)
+		}
+	}
+
+	return nil
+}
+
+func main() {
+	if err := VariantExample(); err != nil {
+		log.Fatal(err)
+	}
+}

examples/std/batch/main.go

@@ -33,9 +33,6 @@ func example() error {
 		return err
 	}
 	conn.SetMaxIdleConns(5)
-	if err != nil {
-		return err
-	}
 	if _, err := conn.Exec(`DROP STREAM IF EXISTS example`); err != nil {
 		return err
 	}