如何从 SQLite 中的表中删除多行

Question

我有一个这样的子查询：

SELECT INTER1.LID1 AS ILID1,INTER1.LID2 AS ILID2 FROM
(SELECT L1.ID1 AS LID1, L1.ID2 AS LID2 FROM Friend F1
INNER JOIN Likes L1
ON F1.ID1 = L1.ID1 AND F1.ID2 = L1.ID2) INTER1
LEFT JOIN Likes L2
ON (INTER1.LID1 = L2.ID2 AND INTER1.LID2 = L2.ID1)
WHERE (L2.ID1 IS NULL AND L2.ID2 IS NULL)

这个的输出如下：

     ID1    ID2

    1641    1468
    1911    1247

现在我必须从 LIKES 表中删除这两行，其格式如下：

  ID1       ID2

 1689       1709
 1709       1689
 1782       1709
 1911       1247
 1247       1468
 1641       1468

我尝试在 SQLite 中使用以下查询来完成此操作：

DELETE FROM Likes 
WHERE EXISTS 
(SELECT INTER1.LID1 AS ILID1,INTER1.LID2 AS ILID2 FROM
(SELECT L1.ID1 AS LID1, L1.ID2 AS LID2 FROM Friend F1
INNER JOIN Likes L1
ON F1.ID1 = L1.ID1 AND F1.ID2 = L1.ID2) INTER1
LEFT JOIN Likes L2
ON (INTER1.LID1 = L2.ID2 AND INTER1.LID2 = L2.ID1)
WHERE (L2.ID1 IS NULL AND L2.ID2 IS NULL));

但它没有按预期工作，它不只删除那些行。

然后我尝试使用 INNER JOIN 解决这个问题，但是 SQLite 中没有 INNER JOIN 与 DELETE 函数相关的功能。

我怎样才能使这项工作。

请帮忙

Answer 1

一次比较两个值：

DELETE FROM Likes
WHERE (ID1, ID2) IN (SELECT ... your original query ...);

Row values 需要 SQLite 3.15 或更高版本。 如果您使用的是早期版本，则必须在单独的步骤中使用单列主键（rowid，或您声明为 INTEGER PRIMARY KEY 的任何内容）查找要删除的行：

DELETE FROM Likes
WHERE rowid IN (SELECT Likes.rowid
                FROM Likes
                JOIN (SELECT ... your original query ...) AS IDs
                  ON Likes.ID1 = IDs.ILID1
                 AND Likes.ID2 = IDs.ILID2);