PHP - MySQL no error message on SQL errors

Question

I'm expecting the following code to produce an error in PHP, but it runs without any sign of error.

<?php

error_reporting(E_ALL);
ini_set('display_errors','On');

$link = mysql_connect('localhost','JUST_ANY_TEXT EVEN WITH SPACES', '');

mysql_select_db('JUST_ANY_TEXT EVEN WITH SPACES', $link);

echo 'LINK RESULT = '.($link?'OK':'ERROR'); //THIS PRINTS: LINK RESULT = OK

echo mysql_query("SELECT INVALID_TEXT FROM TABLE_THAT_DOES_NOT_EXISTS_ANYWHERE PLUS ANY TEXT 3[t3p36g333 3 4638343´tp4oy0i9u54t-9u´089hwpjoeg~,ç");

Does it at least show a warning?

Ry-
– Ry- ♦

2012-02-18 15:37:55 +00:00
Commented Feb 18, 2012 at 15:37 — Ry-
– Ry- ♦, Commented Feb 18, 2012 at 15:37

vbence · Accepted Answer · 2012-02-18 15:46:05Z

3

This works as intended. If you check out the official documentation you will see that there is a return value form most of the functions. You should check that return value to make sure everything is fine.

Also these legacy mysql_* functions are quite outdated. I would suggest using the PDO package instead.

To point out the immediate error in your code. You should use it like:

$success = mysql_select_db('JUST_ANY_TEXT EVEN WITH SPACES', $link);
if (!$success)
    die ('Error selecting the database!');

edited Feb 18, 2012 at 15:46

answered Feb 18, 2012 at 15:39

vbence

20.4k10 gold badges74 silver badges119 bronze badges

Sign up to request clarification or add additional context in comments.

8 Comments

DMF Over a year ago

mysql_connect and mysql_select_db returns TRUE (mysql_connect returns the resource id). only the mysql_query results FALSE.

AgnosticDev Over a year ago

I agree, try using the mysqli functions

DMF Over a year ago

@vbence, $success value is FALSE. This solves my problem! But, is there a way to know when mysql_connect fails? Or I got to try to select a database for this?

vbence Over a year ago

@DMF From mysql_connect's documentation: Returns a MySQL link identifier on success or FALSE on failure.

DMF Over a year ago

I know, but any username I use, it returns MySQL link identifier.

|

Your Common Sense · Accepted Answer · 2012-02-18 15:44:58Z

1

For the mysql_query() you have to check the result of mysql_query() and use mysql_error() to get the MySQL error message:

$query  = "invalid query";
$result = mysql_query($query) or trigger_error(mysql_error()." ".$query);

However, mysql_connect() should raise an error in case of wrong credentials.
Are you sure you can see errors occurred? Whatever PHP errors?

answered Feb 18, 2012 at 15:44

Your Common Sense

158k42 gold badges226 silver badges373 bronze badges

3 Comments

Your Common Sense Over a year ago

then check your credentials if they are really such "ANY TEXT WITH SPACES". Both mysql_connect and mysql_select_db raises a regular PHP error. However, you still can use mysql_error() if you don't sure.

DMF Over a year ago

Now I realized that mysql does not throws error only for the username parameter. The others parameters such as servername and password, throws error when using wrong credentials.

Pacerier Over a year ago

@YourCommonSense, Wow, is colonel back?

Collectives™ on Stack Overflow

PHP - MySQL no error message on SQL errors

2 Answers 2

8 Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

8 Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related