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(PECL maxdb >= 1.0)
maxdb_select_db -- maxdb::select_db — Selects the default database for database queries
$link
, string $dbname
)
The maxdb_select_db() function selects the default
database (specified by the dbname
parameter) to be
used when performing queries against the database connection
represented by the link
parameter.
Note:
This function should only be used to change the default database for the connection. You can select the default database with 4th parameter in maxdb_connect() .
成功时返回 TRUE
, 或者在失败时返回 FALSE
。
Example #1 面向对象风格
<?php
$maxdb = new maxdb ( "localhost" , "MONA" , "RED" , "DEMODB" );
if ( maxdb_connect_errno ()) {
printf ( "Connect failed: %s\n" , maxdb_connect_error ());
exit();
}
if ( $result = $maxdb -> query ( "SELECT SERVERDB FROM USERS WHERE USERNAME='MONA'" )) {
$row = $result -> fetch_row ();
printf ( "Default database is %s.\n" , $row [ 0 ]);
$result -> close ();
}
$maxdb -> select_db ( "XXXXXXXX" );
if ( $result = $maxdb -> query ( "SELECT SERVERDB FROM USERS WHERE USERNAME='MONA'" )) {
$row = $result -> fetch_row ();
printf ( "Default database is %s.\n" , $row [ 0 ]);
$result -> close ();
}
$maxdb -> close ();
?>
Example #2 过程化风格
<?php
$link = maxdb_connect ( "localhost" , "MONA" , "RED" , "DEMODB" );
if ( maxdb_connect_errno ()) {
printf ( "Connect failed: %s\n" , maxdb_connect_error ());
exit();
}
if ( $result = maxdb_query ( $link , "SELECT SERVERDB FROM USERS WHERE USERNAME='MONA'" )) {
$row = maxdb_fetch_row ( $result );
printf ( "Default database is %s.\n" , $row [ 0 ]);
maxdb_free_result ( $result );
}
maxdb_select_db ( $link , "XXXXXXXX" );
if ( $result = maxdb_query ( $link , "SELECT SERVERDB FROM USERS WHERE USERNAME='MONA'" )) {
$row = maxdb_fetch_row ( $result );
printf ( "Default database is %s.\n" , $row [ 0 ]);
maxdb_free_result ( $result );
}
maxdb_close ( $link );
?>
以上例程的输出类似于:
Default database is <...>.Warning: maxdb_select_db(): -10709 Connection failed (RTE:database not running) <...>Warning: maxdb_query(): -10821 Session not connected [] <...>Warning: maxdb_close(): -10821 Session not connected [] <...>