mysql_db_query selects a database, and executes a query on it.
The name of the database that will be selected.
The MySQL query.
Data inside the query should be properly escaped.
The MySQL connection. If the link identifier is not specified, the last link opened by mysql_connect is assumed. If no such link is found, it will try to create one as if mysql_connect had been called with no arguments. If no connection is found or established, an E_WARNING level error is generated.
Returns a positive MySQL result resource to the query result, or false on error. The function also returns true/false for INSERT/UPDATE/DELETE queries to indicate success/failure.
Be aware that this function does NOT switch back to the database you were connected before. In other words, you can't use this function to temporarily run a sql query on another database, you would have to manually switch back. Users are strongly encouraged to use the database.table syntax in their sql queries or mysql_select_db instead of this function.