check is sql statement is valid

[c_pattle]

I have this code which performs a mysql query.  However is there a way I can check to see if the set it returns is empty.  If it is empty I will then change the sql statement.  Thanks

 

$announcement_sql = "select * where annnouncement_for like \"%" . $_POST['for_search'] . "%\" and announcement_verification=\"1\" order by announcement_number desc limit 0, 15";

[AbraCadaver]

$result = mysql_quey($announcement_sql);

if(mysql_num_rows($result) === 0) {
   // no rows were returned
}

[c_pattle]

Thanks I have tried the following code but I always get this error message - "Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /var/www/jon/index.php on line 115". 

 

if (isset($_POST['for_submit'])) {
    $announcement_sql = "select * where annnouncement_for like \"%" . $_POST['for_search'] . "%\" and announcement_verification=\"1\" order by announcement_number desc limit 0, 15";
$num_rows = mysql_num_rows(mysql_query($announcement_sql, $mysql_conn));
if (!$num_rows) {
        $announcement_sql = "select * from announcements where announcement_verification=\"1\" order by announcement_number desc limit 0, 15";
}

[AbraCadaver]

That means that there was an error in your query.  You should check for that as well.  Something like:

 

$result = mysql_query($announcement_sql) or die(mysql_error());

[Pawn]

Aways check the result of mysql_query. The more verbose your error handling, the easier you will find it to debug your code.

 

$sql = "SELECT col FROM tbl_name";
if(!$query = mysql_query($sql)) {
    echo "An error occured on line ".__LINE__.".<br />\n"
    .    "MySQL said: ".mysql_error().".<br /><br />\n"
    .    "Query: ".$sql;
    exit;
}
$num_rows = mysql_num_rows($query);
if($num_rows == 0) {
    echo "No results were returned.<br /><br />\n"
    .    "Query: ".$sql;
}