mysql_query

Description

mysql_query() sends a query to the currently active database on the server that's associated with the specified link identifier. If link_identifier isn't specified, the last opened link is assumed. If no link is open, the function tries to establish a link as if mysql_connect() was called with no arguments, and use it.

mysql_query() returns TRUE (non-zero) or FALSE to indicate whether or not the query succeeded. A return value of TRUE means that the query was legal and could be executed by the server. It does not indicate anything about the number of rows affected or returned. It is perfectly possible for a query to succeed but affect no rows or return no rows.

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

Example 1. mysql_query() <?php $result = mysql_query ("SELECT * WHERE 1=1") or die ("Invalid query"); ?>

The following query is semantically invalid if my_col is not a column in the table my_tbl, so mysql_query() fails and returns FALSE:

Example 2. mysql_query() <?php $result = mysql_query ("SELECT my_col FROM my_tbl") or die ("Invalid query"); ?>

mysql_query() will also fail and return FALSE if you don't have permission to access the table(s) referenced by the query.