Question

我的表结构如下面的desc命令

sr  group   name    status
4   class11 ghanshyam   Joined
3   class11 ghanshyam   Removed
2   class11 ghanshyam   suspended
1   class11 ghanshyam   joined

现在我想获取状态为Removed的组class11中的所有记录。

所以我的查询将是

select * from table where group = 'class11' and status='Removed' group by name

但现在ghanshyam在状态被删除后重新加入了组，我们正在复制条目，因此它不应计入已删除状态，对于已暂停的帐户也是如此。

那么如何从表中获取所需的行

Answer 1

您应该在所有情况下检索记录，如下所示：

select * from table where group = 'class11'

执行此操作后，您可以检查最后一个状态，如果已删除或加入。

Answer 2

SELECT t1.* from [table] t1

INNER JOIN

( SELECT MAX(sr) AS nsr ,[group] ,[name] FROM [table] GROUP BY [group] ,[name] ) t2

ON t2.nsr = t1.sr
AND t1.status='Removed'

Answer 3

试试这个：

SELECT * FROM yourTable WHERE group = 'class11' AND status ='Removed' AND (SELECT MAX(sr) FROM yourTable WHERE group = 'class11' AND status ='Joined') < sr GROUP BY name

希望这会对你有所帮助:) 如有任何澄清，请添加评论。

Answer 4

尝试此查询，它将获得removed

的最大ID的记录

SELECT * FROM tbl_name t WHERE t.sr IN 
  (SELECT max(t1.sr) FROM tbl_name t1 WHERE `group` = 'class11' GROUP BY t1.`name`) 
  AND t.status = 'Removed'

检查这样小提琴： http://sqlfiddle.com/#!9/ef189a/1

从具有重复条目的表中获取记录

4 个答案: