Php/docs/function.mysql-query

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• MySQL Functions
• Send a MySQL query

mysql_query

(PHP 4, PHP 5)

mysql_query — Send a MySQL query

Warning This extension was deprecated in PHP 5.5.0, and it was removed in PHP 7.0.0. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide and related FAQ for more information. Alternatives to this function include:

• mysqli_query()
• PDO::query()

Description

mysql_query ( string $query [, resource $link_identifier = NULL ] ) : mixed

mysql_query() sends a unique query (multiple queries are not supported) to the currently active database on the server that's associated with the specified link_identifier.

Parameters

query

An SQL query

The query string should not end with a semicolon. Data inside the query should be properly escaped.

link_identifier

The MySQL connection. If the link identifier is not specified, the last link opened by mysql_connect() is assumed. If no such link is found, it will try to create one as if mysql_connect() had been called with no arguments. If no connection is found or established, an E_WARNING level error is generated.

Return Values

For SELECT, SHOW, DESCRIBE, EXPLAIN and other statements returning resultset, mysql_query() returns a resource on success, or FALSE on error.

For other type of SQL statements, INSERT, UPDATE, DELETE, DROP, etc, mysql_query() returns TRUE on success or FALSE on error.

The returned result resource should be passed to mysql_fetch_array(), and other functions for dealing with result tables, to access the returned data.

Use mysql_num_rows() to find out how many rows were returned for a SELECT statement or mysql_affected_rows() to find out how many rows were affected by a DELETE, INSERT, REPLACE, or UPDATE statement.

mysql_query() will also fail and return FALSE if the user does not have permission to access the table(s) referenced by the query.

Examples

Example #1 Invalid Query

The following query is syntactically invalid, so mysql_query() fails and returns FALSE.

<?php$result = mysql_query('SELECT * WHERE 1=1');if (!$result) {    die('Invalid query: ' . mysql_error());}?>

Example #2 Valid Query

The following query is valid, so mysql_query() returns a resource.

<?php// This could be supplied by a user, for example$firstname = 'fred';$lastname  = 'fox';// Formulate Query// This is the best way to perform an SQL query// For more examples, see mysql_real_escape_string()$query = sprintf("SELECT firstname, lastname, address, age FROM friends     WHERE firstname='%s' AND lastname='%s'",    mysql_real_escape_string($firstname),    mysql_real_escape_string($lastname));// Perform Query$result = mysql_query($query);// Check result// This shows the actual query sent to MySQL, and the error. Useful for debugging.if (!$result) {    $message  = 'Invalid query: ' . mysql_error() . "\n";    $message .= 'Whole query: ' . $query;    die($message);}// Use result// Attempting to print $result won't allow access to information in the resource// One of the mysql result functions must be used// See also mysql_result(), mysql_fetch_array(), mysql_fetch_row(), etc.while ($row = mysql_fetch_assoc($result)) {    echo $row['firstname'];    echo $row['lastname'];    echo $row['address'];    echo $row['age'];}// Free the resources associated with the result set// This is done automatically at the end of the scriptmysql_free_result($result);?>

See Also

• mysql_connect() - Open a connection to a MySQL Server
• mysql_error() - Returns the text of the error message from previous MySQL operation
• mysql_real_escape_string() - Escapes special characters in a string for use in an SQL statement
• mysql_result() - Get result data
• mysql_fetch_assoc() - Fetch a result row as an associative array
• mysql_unbuffered_query() - Send an SQL query to MySQL without fetching and buffering the result rows