安装程序脚本中的 MySQL 函数

Question

是否可以从 Magento 安装程序脚本中创建函数？我目前有以下代码：

$installer = $this;
$installer->startSetup();
$installer->run("
         DROP function IF EXISTS {$this->getTable('getLatestActivity')};
         CREATE FUNCTION {$this->getTable('getLatestActivity')} (activityid int) RETURNS int(11)
         BEGIN

         set @rank = 0;

         set @matchingId := (select id from (
         SELECT   @rank := @rank+1 AS rank, t_act.id, t_act.date
         FROM      activityupdates ut_act
         LEFT JOIN activityupdates AS t_act ON t_act.ticked = 1
             AND t_act.date <= ut_act.date AND t_act.customer_id = ut_act.customer_id AND t_act.type = ut_act.type
         WHERE ut_act.id = activityid
         ORDER BY t_act.date DESC
         )ranked
         where ranked.rank = 1);
         return @matchingId;
         END;
     ");

但我抛出异常 SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 4 - 不是很有帮助。

为了在 PHPMyAdmin 中运行它，我必须添加有关 DELIMITERS 的行，但我认为这是 GUI 的缺点，而不是需要它们的 FUNCTION 的缺点。如果我包含它们，我只会得到一个有关定义 DELIMITER 的异常。

$installer->run("

         DROP function IF EXISTS `{$this->getTable('getLatestActivity')}`;
         DELIMITER $$
         CREATE FUNCTION `{$this->getTable('getLatestActivity')}` (activityid int) RETURNS int(11)
         BEGIN

         set @rank = 0;

         set @matchingId := (select id from (
         SELECT   @rank := @rank+1 AS rank, t_act.id, t_act.date
         FROM      activityupdates ut_act
         LEFT JOIN activityupdates AS t_act ON t_act.ticked = 1
             AND t_act.date <= ut_act.date AND t_act.customer_id = ut_act.customer_id AND t_act.type = ut_act.type
         WHERE ut_act.id = activityid
         ORDER BY t_act.date DESC
         )ranked
         where ranked.rank = 1);
         return @matchingId;
         END$$

         DELIMITER ;

     ");

错误： SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DELIMITER $$ CREATE FUNCTION getLatestActivity (activityid int)

Answer 1

Mage_Core_Model_Resource_Setup::run() 接受多个查询，以分号分隔给定参数（sql 语句）。这导致函数体被分成多个单独的调用。函数声明不完整，函数创建失败并显示给定的异常消息。

此外，与直接使用 MySQL CLI 客户端（或 PHPMyAdmin）相反，定义分隔符会导致 PDOException. 尼尔斯·普鲁斯 收到了来自 Zend_Db 邮件列表 几年前：

1. 不用担心 DELIMITER，你不需要它。
2. 您必须在两个单独的语句中执行 DROP 和 CREATE。
3. 绕过默认的 ZF 查询方法。

总而言之，以下代码片段将导致函数被创建：

$this->getConnection()->query("DROP function IF EXISTS `{$this->getTable('getLatestActivity')}`");
$this->getConnection()->query("
CREATE FUNCTION `{$this->getTable('getLatestActivity')}` (activityid int) RETURNS int(11)
BEGIN
    set @rank = 0;
    set @matchingId := (select id from (
        SELECT   @rank := @rank+1 AS rank, t_act.id, t_act.date
        FROM      activityupdates ut_act
        LEFT JOIN activityupdates AS t_act ON t_act.ticked = 1
            AND t_act.date <= ut_act.date
            AND t_act.customer_id = ut_act.customer_id
            AND t_act.type = ut_act.type
        WHERE ut_act.id = activityid
        ORDER BY t_act.date DESC
    ) ranked
    where ranked.rank = 1);
    return @matchingId;
END;
");