Question

我想在mysql v 3.23中编写这个sql select语句

select * 
    from radacct 
    where username in ( 
        select username 
            from radcheck 
            where Attribute = 'max-weekly-session'
    );

但是说

ERROR 1064: You have an error in your SQL syntax near 
'select username from radcheck where Attribute= 'max-weekly-session')' 
at line 1

在mysql v 5中这没关系，但我怎样才能在v3.33中做到？

Answer 1

试试这个：

select a.* 
from radacct a 
join radcheck b on a.username = b.username
where b.Attribute = 'max-weekly-session'

Answer 2

符合完全标准的子查询was added in 4.1支持。在此之前，您必须使用JOIN和其他解决方法来实现相同的效果。

请参阅12.2.8.11. Rewriting Subqueries as Joins for Earlier MySQL Versions

Answer 3

select * 
from radacct ra
inner join radcheck on ra.username = rc.username
where rc.Attribute = 'max-weekly-session'

Answer 4

嵌套选择在MySQL版本中不可用＆lt; 4.1

以下工作

select radacct.* 
from radacct inner join radcheck on radacct.username = radcheck.username 
where radcheck.Attribute= 'max-weekly-session'

Answer 5

我需要类似的东西，但这里给出的所有解决方案都会导致从radacct返回多个条目的错误。我通过在radacct键上添加group by来修复此问题。

select ra.* 
from radacct ra
inner join radcheck rc on ra.username = rc.username
where rc.Attribute = 'max-weekly-session'
group by ra.Id

在mysql v 3.23中嵌套选择

5 个答案: