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.