Add OpenDB. #463

Author: kshvakov

clickhouse_options.go

@@ -91,7 +91,7 @@ func (o *Options) fromDSN(in string) error {
 			}
 		}
 	}
-	if secure {
+	if secure && o.TLS == nil {
 		o.TLS = &tls.Config{
 			InsecureSkipVerify: skipVerify,
 		}

clickhouse_std.go

@@ -16,26 +16,44 @@ func init() {
 	sql.Register("clickhouse", &stdDriver{})
 }
 
+func OpenDB(opt *Options) driver.Connector {
+	opt.setDefaults()
+	return &stdDriver{
+		opt: opt,
+	}
+}
+
 type stdDriver struct {
+	opt    *Options
 	conn   *connect
 	commit func() error
 	connID int64
 }
 
+func (d *stdDriver) Driver() driver.Driver {
+	return d
+}
+
+func (d *stdDriver) Connect(context.Context) (_ driver.Conn, err error) {
+	return d.Open("")
+}
+
 func (d *stdDriver) Open(dsn string) (_ driver.Conn, err error) {
 	var (
-		opt    Options
 		conn   *connect
 		connID = int(atomic.AddInt64(&d.connID, 1))
 	)
-	if err = opt.fromDSN(dsn); err != nil {
-		return nil, err
+	if d.opt == nil {
+		d.opt = &Options{}
+		if err = d.opt.fromDSN(dsn); err != nil {
+			return nil, err
+		}
 	}
-	for num := range opt.Addr {
-		if opt.ConnOpenStrategy == ConnOpenRoundRobin {
-			num = int(connID) % len(opt.Addr)
+	for num := range d.opt.Addr {
+		if d.opt.ConnOpenStrategy == ConnOpenRoundRobin {
+			num = int(connID) % len(d.opt.Addr)
 		}
-		if conn, err = dial(opt.Addr[num], connID, &opt); err == nil {
+		if conn, err = dial(d.opt.Addr[num], connID, d.opt); err == nil {
 			return &stdDriver{
 				conn: conn,
 			}, nil

examples/std/open_db.go

@@ -0,0 +1,90 @@
+package main
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/ClickHouse/clickhouse-go/v2"
+)
+
+func example() error {
+	conn := sql.OpenDB(clickhouse.OpenDB(&clickhouse.Options{
+		Addr: []string{"127.0.0.1:9000"},
+		Auth: clickhouse.Auth{
+			Database: "default",
+			Username: "default",
+			Password: "",
+		},
+	}))
+	conn.SetMaxIdleConns(5)
+	conn.SetMaxOpenConns(10)
+	conn.SetConnMaxLifetime(time.Hour)
+	ctx := clickhouse.Context(context.Background(), clickhouse.WithSettings(clickhouse.Settings{
+		"max_block_size": 10,
+	}), clickhouse.WithProgress(func(p *clickhouse.Progress) {
+		fmt.Println("progress: ", p)
+	}))
+	if err := conn.PingContext(ctx); err != nil {
+		if exception, ok := err.(*clickhouse.Exception); ok {
+			fmt.Printf("Catch exception [%d] %s \n%s\n", exception.Code, exception.Message, exception.StackTrace)
+		}
+		return err
+	}
+	if _, err := conn.ExecContext(ctx, `DROP TABLE IF EXISTS example`); err != nil {
+		return err
+	}
+	_, err := conn.ExecContext(ctx, `
+		CREATE TABLE IF NOT EXISTS example (
+			Col1 UInt8,
+			Col2 String,
+			Col3 DateTime
+		) engine=Memory
+	`)
+	if err != nil {
+		return err
+	}
+	scope, err := conn.Begin()
+	if err != nil {
+		return err
+	}
+	{
+		batch, err := scope.PrepareContext(ctx, "INSERT INTO example (Col1, Col2, Col3)")
+		if err != nil {
+			return err
+		}
+		for i := 0; i < 10; i++ {
+			if _, err := batch.Exec(uint8(i), fmt.Sprintf("value_%d", i), time.Now()); err != nil {
+				return err
+			}
+		}
+	}
+	if err := scope.Commit(); err != nil {
+		return err
+	}
+	rows, err := conn.QueryContext(ctx, "SELECT Col1, Col2, Col3 FROM example WHERE Col1 >= $1 AND Col2 <> $2 AND Col3 <= $3", 0, "xxx", time.Now())
+	if err != nil {
+		return err
+	}
+	for rows.Next() {
+		var (
+			col1 uint8
+			col2 string
+			col3 time.Time
+		)
+		if err := rows.Scan(&col1, &col2, &col3); err != nil {
+			return err
+		}
+		fmt.Printf("row: col1=%d, col2=%s, col3=%s\n", col1, col2, col3)
+	}
+	rows.Close()
+	return rows.Err()
+}
+
+func main() {
+	if err := example(); err != nil {
+		log.Fatal(err)
+	}
+}