mysql - PostgreSQL 上的 Doctrine SQL 查询 : works on MySQL, 不会

Question

这是由 Doctrine ORM 的 Taggable 扩展自动生成的查询。

SELECT t.id AS t__id, t.name AS t__name, COUNT(DISTINCT i.id) AS i__0,
   (COUNT(DISTINCT i.id)) AS i__1
FROM taggable_tag t
LEFT JOIN cms__model__image_taggable_tag c ON (t.id = c.tag_id)
LEFT JOIN image i ON i.id = c.id
WHERE t.id IN
    (SELECT doctrine_subquery_alias.id
     FROM
       (SELECT DISTINCT t2.id, (COUNT(DISTINCT i2.id)) AS i2__1
        FROM taggable_tag t2
        LEFT JOIN cms__model__image_taggable_tag c2 ON (t2.id = c2.tag_id)
        LEFT JOIN image i2 ON i2.id = c2.id
        GROUP BY t2.id HAVING i2__1 > 0
        ORDER BY i2__1 DESC LIMIT 10) AS doctrine_subquery_alias)
GROUP BY t.id HAVING i__1 > 0
ORDER BY i__1 DESC

它在使用 MySql 时有效，但不适用于 PostgreSql。

我得到:column i2__1 not found 或 column i__2 not found。

使用 COUNT(DISTINCT) 时是否不允许使用别名？
此查询在 PostgreSql 上应该如何工作？

Answer 1

您可以尝试在子选择的 HAVING 子句中将 i2__1 替换为 COUNT(DISTINCT i2.id)，或者删除 COUNT(DISTINCT i2.id) 两边的括号。

您可能还必须将 t__name 添加到主选择的 GROUP BY 子句中。