Question

我有以下数据库：

Account  Month   Pass

1        July    No
2        July    No
3        July    Yes
4        July    No
5        July    Yes

1        August  No
2        August  Yes
3        August  Yes
4        August  Yes
5        August  Yes

我想要：

1）在7月失败但在8月通过的事情
2）与上一个查询相同的帐号，但在8月而不是7月

因此，先前示例的结果将是：

Account  Month   

2        July    
2        August
4        July
4        August

Answer 1

如果您可以将给定帐户的结果放在一个行而不是多行中，那么--protocol=TCP --port=3307应该做您想要的事情：

man mysqldump

也就是说，我强烈建议您按照Tim在评论中的建议，将数据放入带有日期列的单个表中。

Answer 2

select a.Account from temp a where a.Month = 'July' and a.pass = 'No'
INTERSECT
select a.Account from temp a where a.Month = 'August' and a.pass = 'Yes'

或

select a.Account from temp a where a.Month = 'July' and a.pass = 'No' 
and a.Account in (select a.Account from temp a where a.Month = 'August' and a.pass = 'Yes')

或

select * from temp a, temp b 
where a.Account = b.Account and a.month <> b.Month 
and a.Month = 'July' and a.pass = 'No' and b.Month = 'August' and b.pass = 'Yes'

您可以对问题2使用相同的查询，只需更改条件

Answer 3

我没有Teradata。以下查询在mssql中运行正常。除非有一些语法更改，否则大多数sql中应该相同

您将需要对帐号（标识符）进行联接，以通过以下表中的表通过失败/通过条件来标识帐号，

select select a.AccountNumber from dbo.MonthlyResultAugust a join dbo.MonthlyResultJuly b on a.AccountNumber=b.AccountNumber where lower(a.Pass)='yes' and lower(b.Pass)='no';

然后对于所需的输出，您可以合并两个源表并从上一个查询中提取与帐号匹配的数据。组合查询看起来像

    select AccountNumber, Month from 
(select * from MonthlyResultAugust union select * from MonthlyResultJuly) as combined
 where accountNumber in 
 ( select a.AccountNumber from MonthlyResultAugust a join MonthlyResultJuly b 
 on a.AccountNumber=b.AccountNumber where lower(a.Pass)='yes' and lower(b.Pass)='no') order by AccountNumber;

Answer 4

这是我的解决方案：

SELECT Account, [Month]
  FROM pass_table t
 WHERE [Month] = 'July' AND Pass = 'No'
   AND EXISTS (SELECT 1 FROM pass_table [Month] = 'August' AND Pass = 'Yes' AND Account = t.Account)

UNION

SELECT Account, [Month]
  FROM pass_table t
 WHERE [Month] = 'August' AND Pass = 'Yes'
   AND EXISTS (SELECT 1 FROM pass_table [Month] = 'July' AND Pass = 'No' AND Account = t.Account)

SQL-在几个条件下从数据库检索记录

4 个答案: