You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: clickhouse_open.go
    path of file: ./repos/gf/contrib/drivers/clickhouse
    
    the code of the file until where you have to start completion: // Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.

package clickhouse

import (
	"database/sql"
	"fmt"
	"net/url"

	"github.com/gogf/gf/v2/database/gdb"
	"github.com/gogf/gf/v2/errors/gcode"
	"github.com/gogf/gf/v2/errors/gerror"
	"github.com/gogf/gf/v2/text/gregex"
)

// Open creates and returns an underlying sql.DB object for clickhouse.
func (d *Driver) Open(config *gdb.ConfigNode) (db *sql.DB, err error) {
	source := config.Link
	// clickhouse://username:password@host1:9000,host2:9000/database?dial_timeout=200ms&max_execution_time=60
	if config.Link != "" {
		// ======
    
func (d *Driver) Open(config *gdb.ConfigNode) (db *sql.DB, err error) {
	source := config.Link
	// clickhouse://username:password@host1:9000,host2:9000/database?dial_timeout=200ms&max_execution_time=60
	if config.Link != "" {
		// ============================================================================
		// Deprecated from v2.2.0.
		// ============================================================================
		// Custom changing the schema in runtime.
		if config.Name != "" {
			source, _ = gregex.ReplaceString(replaceSchemaPattern, "@$1/"+config.Name, config.Link)
		} else {
			// If no schema, the link is matched for replacement
			dbName, _ := gregex.MatchString(replaceSchemaPattern, config.Link)
			if len(dbName) > 0 {
				config.Name = dbName[len(dbName)-1]
			}
		}
	} else {
		if config.Pass != "" {
			source = fmt.Sprintf(
				"clickhouse://%s:%s@%s:%s/%s?debug=%t",
				config.User, url.PathEscape(config.Pass),
				config.Host, config.Port, config.Name, config.Debug,
			)
		} else {
			source = fmt.Sprintf(
				"clickhouse://%s@%s:%s/%s?debug=%t",
				config.User, config.Host, config.Port, config.Name, config.Debug,
			)
		}
		if config.Extra != "" {
			source = fmt.Sprintf("%s&%s", source, config.Extra)
		}
	}
	if db, err = sql.Open(driverName, source); err != nil {
		err = gerror.WrapCodef(
			gcode.CodeDbOperationError, err,
			`sql.Open failed for driver "%s" by source "%s"`, driverName, source,
		)
		return nil, err
	}
	return
}