PHP Manual
MySQL Functions
Send an SQL query to MySQL without fetching and buffering the result rows

mysql_unbuffered_query

(PHP 4 >= 4.0.6, PHP 5)

mysql_unbuffered_query — Send an SQL query to MySQL without fetching and buffering the result rows

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. Alternatives to this function include:

See: Buffered and Unbuffered queries

Description

mysql_unbuffered_query(string $query, resource $link_identifier = NULL): resource

mysql_unbuffered_query() sends the SQL query query to MySQL without automatically fetching and buffering the result rows as mysql_query() does. This saves a considerable amount of memory with SQL queries that produce large result sets, and you can start working on the result set immediately after the first row has been retrieved as you don't have to wait until the complete SQL query has been performed. To use mysql_unbuffered_query() while multiple database connections are open, you must specify the optional parameter link_identifier to identify which connection you want to use.

Parameters

query

The SQL query to execute.

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 or EXPLAIN statements, mysql_unbuffered_query() returns a resource on success, or false on error.

For other type of SQL statements, UPDATE, DELETE, DROP, etc, mysql_unbuffered_query() returns true on success or false on error.

Notes

Note:
The benefits of mysql_unbuffered_query() come at a cost: you cannot use mysql_num_rows() and mysql_data_seek() on a result set returned from mysql_unbuffered_query(), until all rows are fetched. You also have to fetch all result rows from an unbuffered SQL query before you can send a new SQL query to MySQL, using the same link_identifier.