[Bug] use employees error, get dataset error 6: Unknown database 'employees'

[dongzl]

What would you like to be added:

Why is this needed:

Start arana, use this program connect to it error:

package sql

import (
	"database/sql"
	"fmt"
	_ "github.com/go-sql-driver/mysql"
	"log"
	"testing"
)

func TestName(t *testing.T) {
	mdb, err := sql.Open("mysql", "root:123456@tcp(127.0.0.1:13306)/employees?time_zone=%27Asia%2FShanghai%27&allowAllFiles=true")
	if err != nil {
		log.Fatalf("Open db err %v", err)
	}
	_, err1 := mdb.Exec("show tables")
	if err1 != nil {
		log.Fatalf("Exec show tables err %v", err1)
	}
	_, err2 := mdb.Exec(fmt.Sprintf("use `%s`", "employees"))
	if err2 != nil {
		log.Fatalf("Exec use db err %v", err2)
	}
}

2023-01-11T10:31:47.077+0800    ERROR   mysql/execute_handle.go:102     get dataset error 6: Unknown database 'employees' (errno 1049) (sqlstate 42000)

[wang1309]

原因：协议头为 ComQuery 类型，使用终端执行这条命令协议头为：ComInitDB。由于协议头为 ComQuery，导致请求直接被透传到 mysql 实例。
解决方案：待定