Question

我有5张桌子。我想让表1中的特定用户不在table2，table3，table4和table5中。有人可以帮助我:)）

table1(userid,discount)
table2(userid,discount)
table3(userid,discount)
table4(userid,discount)
table5(userid,discount)

Answer 1

以下查询：

SELECT userid
FROM table1 AS t1
WHERE NOT EXISTS (
  SELECT 1 
  FROM (
    SELECT userid
    FROM table2
    UNION 
    SELECT userid
    FROM table3
    UNION 
    SELECT userid
    FROM table4
    UNION 
    SELECT userid
    FROM table5) AS t2
  WHERE t1.userid = t2.userid)

返回所有其他表格中不存在的table1用户。

Demo here

如果您还希望所有table2用户都不在其他任何表中，那么您可以修改上述查询，以便从table2返回用户并在这两个查询之间执行UNION：

SELECT userid
FROM table1 AS t1
WHERE NOT EXISTS (
  SELECT 1 
  FROM (
    SELECT userid
    FROM table2
    UNION 
    SELECT userid
    FROM table3
    UNION 
    SELECT userid
    FROM table4
    UNION 
    SELECT userid
    FROM table5) AS t2
  WHERE t1.userid = t2.userid)

UNION ALL

SELECT userid
FROM table2 AS t1
WHERE NOT EXISTS (
  SELECT 1 
  FROM (
    SELECT userid
    FROM table1
    UNION 
    SELECT userid
    FROM table3
    UNION 
    SELECT userid
    FROM table4
    UNION 
    SELECT userid
    FROM table5) AS t2
  WHERE t1.userid = t2.userid)

Demo here

可以轻松扩展上述内容，以便合并所有表格中的用户。但是，我不得不承认，它变得非常冗长！

在sql中找不到常见用户

1 个答案: