drupal7 多数据库操作

1、定义数据库名称，用户名，前缀，编码等。
$databases = array(
   'default' =>
   array(
     'default' =>
     array(
       'driver' => 'mysql',
       'database' => 'databasename',
       'username' => 'username',
       'password' => 'password',
       'host' => 'localhost',
       'port' => 3306,
       'prefix' => 'myprefix_',
       'collation' => 'utf8_general_ci',
     ),
   ),
'legacy' =>
   array(
     'default' =>
     array(
       'driver' => 'mysql',
       'database' => 'legacydatabasename',
       'username' => 'legacyusername',
       'password' => 'legacypassword',
       'host' => 'legacy',
       'port' => 6060,
       'prefix' => 'legacyprefix_',
       'collation' => 'utf8_general_ci',
     ),
   ),

);


2、数据库的切换
//从其他数据库查询信息
db_set_active('legacy');
$result = db_query("select * from table where uid = :uid", array(':uid' => $user->uid));

//切换到默认数据库
db_set_active('default');