sybase_select_db() sets the current active database on the server that's associated with the specified link identifier. If no link identifier is specified, the last opened link is assumed. If no link is open, the function will try to establish a link as if sybase_connect() was called, and use it.
Returns TRUE on success or FALSE on failure.
Every subsequent call to sybase_query() will be made on the active database.
See also sybase_connect(), sybase_pconnect() and sybase_query()