Sql连接表

Question

我有两个表作为A，B。表A保存我的类别名称，表B保存 我的fk_tbl_A，时间，机器名称。

我想计算一下我用于每台机器的时间，并按fk_abl_A分组 我在SQL 2012中编写了以下代码：

select sum(cast(a.during_time as int))
from dbo.sabt_bazdid as a join
     dbo.ability as b
     on a.fk_operator_ability = b.id
Group by a.fk_operator_ability 

这里的代码运行良好，但是当我想在表A中显示类别的名称时， Sql显示错误。

select b.name, sum(cast(a.during_time as int))
from dbo.sabt_bazdid as a join
     dbo.ability as b
     on a.fk_operator_ability = b.id
Group by a.fk_operator_ability 

请帮我解决问题 感谢。

Answer 1

b.name不在group by子句中。您需要将其放在那里或将其放在聚合函数中：

select b.name, sum(cast(a.during_time as int))
from dbo.sabt_bazdid as a join
     dbo.ability as b
     on a.fk_operator_ability = b.id
Group by b.name, a.fk_operator_ability;

Answer 2

您需要将b.name放在group by子句中或聚合函数中。只需将b.name属性放在group by子句中。

select b.name,sum(cast(a.during_time as int))
from dbo.sabt_bazdid as a join
     dbo.ability as b
     on a.fk_operator_ability = b.id
Group by a.fk_operator_ability ,b.name

这是运行查询。