如何使用 Zend_Db_Select 更改带有联接的查询中的列顺序

Question

我有相当复杂的查询，我可以使用 Zend_Db_Select 逐步构建它。查询看起来像这样：

SELECT `subscribers`.`subscriber_id`, `subscribers`.`email_address`, `subscribers`.`first_name`,
`subscribers`.`last_name`, `t1`.`value` AS `'SingleLineField'`, `t2`.`value` AS `'MultilineField'`,
`t3`.`value` AS `'CheckboxField'`
FROM `subscribers`
INNER JOIN (SELECT subscriber_id
            FROM subscribers
            WHERE list_id =68 AND state=1
            LIMIT 0, 25) AS `s` ON subscribers.subscriber_id = s.subscriber_id
LEFT JOIN `subscribers_custom_data_string` AS `t1` ON subscribers.subscriber_id=t1.subscriber_id AND t1.field_id=177
LEFT JOIN `subscribers_custom_data_string` AS `t2` ON subscribers.subscriber_id=t2.subscriber_id AND t2.field_id=178
LEFT JOIN (SELECT subscribers_multivalued.subscriber_id, field_id, GROUP_CONCAT(value SEPARATOR ',') AS value
           FROM subscribers_multivalued
           INNER JOIN (SELECT subscriber_id
                       FROM subscribers
                       WHERE list_id =68 AND state=1
                       LIMIT 0, 25) AS s1 ON subscribers_multivalued.subscriber_id=s1.subscriber_id
           WHERE field_id=179
           GROUP BY subscribers_multivalued.subscriber_id, field_id) AS `t3` ON subscribers.subscriber_id=t3.subscriber_id AND t3.field_id=179

但现在我需要能够动态更改列的顺序，以便能够将上述查询转换为类似的内容：

SELECT  `subscribers`.`subscriber_id`, `subscribers`.`email_address` , `t1`.`value` AS `'SingleLineField'`, `t2`.`value` AS `'MultilineField'`,
`t3`.`value` AS `'CheckboxField'`, `subscribers`.`first_name`,
`subscribers`.`last_name`
FROM `subscribers`
INNER JOIN (SELECT subscriber_id
            FROM subscribers
            WHERE list_id =68 AND state=1
            LIMIT 0, 25) AS `s` ON subscribers.subscriber_id = s.subscriber_id
LEFT JOIN `subscribers_custom_data_string` AS `t1` ON subscribers.subscriber_id=t1.subscriber_id AND t1.field_id=177
LEFT JOIN `subscribers_custom_data_string` AS `t2` ON subscribers.subscriber_id=t2.subscriber_id AND t2.field_id=178
LEFT JOIN (SELECT subscribers_multivalued.subscriber_id, field_id, GROUP_CONCAT(value SEPARATOR ',') AS value
           FROM subscribers_multivalued
           INNER JOIN (SELECT subscriber_id
                       FROM subscribers
                       WHERE list_id =68 AND state=1
                       LIMIT 0, 25) AS s1 ON subscribers_multivalued.subscriber_id=s1.subscriber_id
           WHERE field_id=179
           GROUP BY subscribers_multivalued.subscriber_id, field_id) AS `t3` ON subscribers.subscriber_id=t3.subscriber_id AND t3.field_id=179                         

或者例如，类似这样的内容：

SELECT  `subscribers`.`subscriber_id`, `t1`.`value` AS `'SingleLineField'`, `t2`.`value` AS `'MultilineField'`,
`t3`.`value` AS `'CheckboxField'`, `subscribers`.`email_address`, `subscribers`.`first_name`,
`subscribers`.`last_name`
FROM `subscribers`
INNER JOIN (SELECT subscriber_id
            FROM subscribers
            WHERE list_id =68 AND state=1
            LIMIT 0, 25) AS `s` ON subscribers.subscriber_id = s.subscriber_id
LEFT JOIN `subscribers_custom_data_string` AS `t1` ON subscribers.subscriber_id=t1.subscriber_id AND t1.field_id=177
LEFT JOIN `subscribers_custom_data_string` AS `t2` ON subscribers.subscriber_id=t2.subscriber_id AND t2.field_id=178
LEFT JOIN (SELECT subscribers_multivalued.subscriber_id, field_id, GROUP_CONCAT(value SEPARATOR ',') AS value
           FROM subscribers_multivalued
           INNER JOIN (SELECT subscriber_id
                       FROM subscribers
                       WHERE list_id =68 AND state=1
                       LIMIT 0, 25) AS s1 ON subscribers_multivalued.subscriber_id=s1.subscriber_id
           WHERE field_id=179
           GROUP BY subscribers_multivalued.subscriber_id, field_id) AS `t3` ON subscribers.subscriber_id=t3.subscriber_id AND t3.field_id=179                 

问题是我无法使用方法来自 Zend_Db_Select 多次（在这种情况下它将生成新的联接，这不是我想要的）来更改查询中电子邮件、名字和姓氏字段的顺序。您对如何解决这个问题有什么想法吗？

Answer 1

您可以使用 ->columns() 方法来选择所需的列。
在 from 方法中使用空数组，然后使用 columns() 调用，即使内部有一个大的 Zend_Db_Expr，您也可以决定按照您想要的方式和顺序编写选择参数。