sqlite - 如何在 SQLite 中删除具有 2 列作为复合主键的多行？

Question

我需要删除 SQLite 表中的一些行，其中两列作为主键，如下所示:

DELETE FROM apt_lang 
WHERE (apt_fk, apt_lang_fk) NOT IN ((42122,"en"),(42123,"es"),(42123,"en"))

这适用于 Oracle 和 MySQL，但不适用于 SQLite。

谁能帮帮我？

Answer 1

首先，找出要删除的行。最简单的方法是使用连接:

SELECT *
FROM apt_lang
JOIN (SELECT 42122 AS apt_fk, 'en' AS apt_lang_fk UNION ALL
      SELECT 42123          , 'es'                UNION ALL
      SELECT 42123          , 'en'                         )
USING (apt_fk, apt_lang_fk)

要将其与 DELTE 一起使用，请检查 EXISTS 是否匹配:

DELETE FROM apt_lang
WHERE NOT EXISTS (SELECT 1
                  FROM apt_lang AS a2
                  JOIN (SELECT 42122 AS apt_fk, 'en' AS apt_lang_fk UNION ALL
                        SELECT 42123          , 'es'                UNION ALL
                        SELECT 42123          , 'en'                         )
                  USING (apt_fk, apt_lang_fk)
                  WHERE apt_fk      = apt_lang.apt_fk
                    AND apt_lang_fk = apt_lang.apt_lang_fk)

或获取 ROWID子查询的 s 并检查那些:

DELETE FROM apt_lang
WHERE rowid NOT IN (SELECT apt_lang.rowid
                    FROM apt_lang
                    JOIN (SELECT 42122 AS apt_fk, 'en' AS apt_lang_fk UNION ALL
                          SELECT 42123          , 'es'                UNION ALL
                          SELECT 42123          , 'en'                         )
                    USING (apt_fk, apt_lang_fk))