mysql_query() is the powerful PHP function tasked with handling the execution of all SQL statements against the currently active database connection string. It handles all variations of SQL commands, including SELECT, INSERT, UPDATE, DELETE, etc, and always returns false if the command execution should fail. However, only on SELECT does it bother returning a valid result set – the rest of the time it returns true.

So how do we know if a mysql_query() function call has returned a result set?

Actually the answer is pretty simple – we simply check if the returned object is a boolean with the basic is_bool function!

In practice:

$result = mysql_query("SELECT * FROM table");
if (is_bool($result) == false){
//we have a result set
} else {
//we don't have a result set


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