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maxdb_select_db

maxdb::select_db

(PECL maxdb >= 1.0)

maxdb_select_db -- maxdb::select_dbSelects the default database for database queries

说明

bool maxdb_select_db ( resource $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() .

返回值

成功时返回 TRUE , 或者在失败时返回 FALSE

范例

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 [] <...>

参见

  • maxdb_connect() - Open a new connection to the MaxDB server
  • maxdb_real_connect() - Opens a connection to a MaxDB server
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