my_bool
mysql_change_user(MYSQL *mysql,
const char *user,
const char *password,
const char *db)
Changes the user and 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_change_user()
fails if
the connected user cannot be authenticated or does not have
permission to use the database. In this case, the user and
database are not changed.
Pass a db
parameter of
NULL
if you do not want to have a default
database.
This function resets the session state as if one had done a
new connect and reauthenticated. (See
Section 3.6.6, “Automatic Reconnection Control”.) It always performs a
ROLLBACK
of
any active transactions, closes and drops all temporary
tables, and unlocks all locked tables. It resets session
system variables to the values of the corresponding global
system variables, releases prepared statements, closes
HANDLER
variables, and releases
locks acquired with GET_LOCK()
.
These effects occur even if the user did not change.
To reset the connection state in a more lightweight manner
without changing the user, use
mysql_reset_connection()
.
The same that you can get from
mysql_real_connect()
, plus:
-
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.
-
The MySQL server does not implement this command (probably an old server).
-
The user or password was wrong.
-
The database did not exist.
-
The user did not have access rights to the database.
-
The database name was too long.