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mysql_real_escape_string
MySQL Functions
PHP Manual

# mysql_query

(PHP 4, PHP 5)

mysql_query — Send a MySQL query

### Description

resource mysql_query ( string `$query` [, resource `$link_identifier` ] )

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`

  A 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() was called with no arguments. If by chance 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 a 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 $row['age'];
}
// Free the resources associated with the result set
// This is done automatically at the end of the script
mysql_free_result($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 a 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

mysql_ping
mysql_real_escape_string
MySQL Functions
PHP Manual