How does the mysql_query function in PHP handle the return values of SQL statements, and why is it important to check and handle these values?

The mysql_query function in PHP returns a resource for SELECT, SHOW, DESCRIBE, EXPLAIN, and other statements that return a result set. It returns true or false for other types of SQL statements. It is important to check and handle these return values to ensure that the query was executed successfully and to handle any errors that may occur during the query execution.

$query = "SELECT * FROM table_name";
$result = mysql_query($query);

if($result){
    // Query executed successfully
    // Process the result set
} else {
    // Query failed
    echo "Error: " . mysql_error();
}