Comments on: How to change the default database in MySQL

By: Xaprb

Xaprb — Sun, 12 Oct 2008 12:43:11 +0000

Shantanu, that’s a trick I also use sometimes to help me figure out which table a column comes from. Developers think it’s obvious, but when you’re a consultant it’s tough to optimize queries when you don’t know the schema by heart!

By: Shantanu Oak

Shantanu Oak — Sun, 12 Oct 2008 10:43:03 +0000

>> all table names in the query are fully qualified so thereâ€™s no ambiguity
If that is all you are looking for, then “explain extended” and then show warnings will let you know the ‘database.table’ used by MySQL

By: Mikael Fridh

Mikael Fridh — Sun, 12 Oct 2008 08:42:33 +0000

By: Eric Day

Eric Day — Sun, 12 Oct 2008 06:54:23 +0000

I just tested select_db() with an empty DB name, which issues a COM_DB_INIT at the protocol layer, and it doesn’t work. It sends the “correct” packet, with a 0 length DB, but you get back an error: “No database selected”. I suppose a bug/feature request could be filed to change the behavior of this request. :)

By: Dmitry Lenev

Dmitry Lenev — Sun, 12 Oct 2008 06:10:23 +0000

MySQL test suite sometimes uses approach described by Brian. In other cases it uses special option for mysqltest’s “connect” command (indeed, it is probably not an approach that can be used in your case).