int mysql_select_db(MYSQL *mysql, const char
*db)
Causes the database specified by db to become
the default (current) database on the connection specified by
mysql. In subsequent queries, this database
is the default for table references that include no explicit
database specifier.
mysql_select_db() fails unless
the connected user can be authenticated as having permission to
use the database.
Zero for success. Nonzero if an error occurred.
Commands were executed in an improper order.
The MySQL server has gone away.
The connection to the server was lost during the query.
An unknown error occurred.