问mysql表drupal中的"created“和"updated”列

EN

$schema['table'] = array(
  'fields' => array(
    'created' => array(
      'mysql_type' => 'datetime',
      'not null ' => TRUE,
      'default' => format_date(time(), 'custom', 'Y-m-d 00:00:00'),
    ),
    'updated' => array(
      'mysql_type' => 'timestamp',
      'not null' => TRUE,
    ),
  ),
  //other parts of the schema (indexes, keys...)
);

//Automatically set created datetime for current timestamp upon insert
$query = db_query('
  CREATE TRIGGER triggername BEFORE INSERT ON tablename FOR EACH ROW BEGIN SET
    NEW.created=NOW(); END
');

//Automatically update 'updated' to current timestamp whenever a row is changed
$query = db_query('
  ALTER TABLE tablename
  MODIFY updated TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
');

         * Implementation of hook_install()
 * @see http://api.drupal.org/api/function/hook_install/
 * this is called when a module is installed, providing a chance
 * to create any database tables specific our module
 */


function upgrade_inforegistration_install()
{
 $query =  db_query('
    CREATE TRIGGER `mydb`.`mytriggername`
    AFTER INSERT ON `mytrigtable`
    FOR EACH ROW
    BEGIN
    INSERT INTO `mydb`.`myaffectedtable`
        (`day`, `uid`, `anotherfield`)
    VALUES (UNIX_TIMESTAMP(NOW()), NEW.uid, `1`);
    END
    ');
}

function moduleName_schema() {
    $schema['tableName'] = array(
        'fields' => array(
            'id' => array(
                'type' => 'serial',
                'not null' => TRUE,
            ),
            'colName' => array(
                'mysql_type' => 'timestamp',
                'not null' => TRUE
            ),
            ....other fields..
            ....
        ),
        'primary key' => array('id'),
    );
    return $schema;
}


function bd_contact_enable() {
  db_query('
    ALTER TABLE {bd_contact} 
    MODIFY created TIMESTAMP NOT NULL 
    DEFAULT CURRENT_TIMESTAMP 
    ON UPDATE CURRENT_TIMESTAMP'
  );
}