我应该在Sql数据库查询中使用Sql.Stmt还是字符串?

Hi in database/sql package I can execute a query in two ways:

  • First way: using Sql.Stmt

    var DeletePermissionStmt *sql.Stmt
    DeletePermissionStmt, err = database.Prepare(`DELETE FROM permission WHERE permission_id=$1`)
    
    if err != nil {
         log.Errorf("can't prepare delete permission statement: %s", err.Error())
    }
    
    transaction, err := database.Begin()  // assume postgres database is defined previously
    
    if err != nil {
         log.WithFields(logFields).Errorf("can't start transaction: %s", err.Error())
    
    
    return err
    }
     _, err := transaction.Stmt(DeletePermissionStmt).Exec(permission_id)
    
  • Second way: using string

    var DeletePermissionStmt string
    DeletePermissionStmt = `DELETE FROM permission WHERE permission_id=$1`
    
    transaction, err := database.Begin()  // assume postgres database is defined previously
    
    if err != nil {
    log.WithFields(logFields).Errorf("can't start transaction: %s", err.Error())
    
    
    return err
    }
     _, err := transaction.Exec(DeletePermissionStmt,permission_id)
    

The only difference That I know that its is not possible to use sql.Stmt when you are returning something for example Insert Into FOO(f1,f2,f3) Values(v1,v2,v3) returning f_id Is there any other differences? and when should I use each one?

Using the Stmt helps you avoid sql injection from the user.

From wikipedia:

Prepared statements are resilient against SQL injection, because parameter values, which are transmitted later using a different protocol, need not be correctly escaped. If the original statement template is not derived from external input, SQL injection cannot occur.