How to know which database is in use currently? For using a particular database, MySQL has <code>Use </code> statement. After you execute USE statement, by default all the query will be executed against the database mentioned in USE statement.
For using other database after this statement, you can write add database name before table name:
Now, this USE statement is issued deep inside a badly written script and you do not want to bother searching deep inside code for knowing the current database in use. For that just issue -
<?php mysql_query("select database()"); ?>
For getting the list of database, you have access to, issue