Description
int mysql_query(string query, int
[
link_identifier]
);
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.
The query string should not end with a semicolon.
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() 1
2 <?php
3 $result = mysql_query ("SELECT * WHERE 1=1")
4 or die ("Invalid query");
5 ?>
6 |
|
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() 1
2 <?php
3 $result = mysql_query ("SELECT my_col FROM my_tbl")
4 or die ("Invalid query");
5 ?>
6 |
|
mysql_query() will also fail and return FALSE
if you don't have permission to access the table(s) referenced by
the query.
Assuming the query succeeds, you can call
mysql_affected_rows() to find out how many
rows were affected (for DELETE, INSERT, REPLACE, or UPDATE
statements). For SELECT statements,
mysql_query() returns a new result identifier
that you can pass to mysql_result(). When you
are done with the result set, you can free the resources
associated with it by calling
mysql_free_result().
See also: mysql_affected_rows(),
mysql_db_query(),
mysql_free_result(),
mysql_result(),
mysql_select_db(), and
mysql_connect().
