PHP Mysql Tutorials, Function, mysql

Topic

What is mysql_error() function in PHP?
How does mysql_error() works?

Explanation

mysql_error() function returns the text error message from previous MySQL operation.

Syntax

string mysql_error ( [resource link_identifier])

Returns the error text from the last MySQL function, or '' (the empty string) if no error occurred.

mysql_error() function is used to retrieve the error text from the most recently executed MySQL function

Example:

<?php

//Attempt to connect to the default database server

$link = mysql_connect("mysql_host", "mysql_user", "mysql_password")
or die ("Could not connect");

//select non existing database

if (!mysql_select_db("my_database", $link)) {

//prints error message on selecting non existing database

echo mysql_errno($link) . ": " . mysql_error($link). "\n";
}

//Attempt to select database

mysql_select_db("my_database", $link);

//Execute query

if (!mysql_query("SELECT * FROM nonexistenttable", $link)) {

//Display error report

echo mysql_errno($link) . ": " . mysql_error($link). "\n";
}

mysql_close($link);

?>

In the above example, the query fails due to non existance of database 'my_database' and table 'nonexistenttable'. Here 'mysql_errno' function prints the occured error number and 'mysql_error' prints the text error message from the executed query.

RESULT:

1049: Unknown database 'nonexistentdb'
1146: Table 'my_database.nonexistenttable' doesn't exist

See also: mysql_errno() and MySQL error messages

mysql_error() Function in PHP