select *
FROM dbo.t_Other AS a LEFT OUTER JOIN
dbo.t_BillType AS b ON a.F_Type = b.F_Name LEFT OUTER JOIN
dbo.t_Emp AS c ON a.F_EmpID = c.F_ID LEFT OUTER JOIN
(case when b.F_Mode='供应商' then t_Supplier when d.F_Mode='客户' then t_Client else t_Dept end)
AS d ON a.F_UnitID = d.F_ID
我是根据不同选项选择不同的表连接,case when 错了,怎么改
------解决方案--------------------
CASE WHEN 的结果是个值，不是集。所以不能用 LEFT JOIN 关联
------解决方案--------------------
- SQL code
--case when不能那样用的select a.*, case when b.F_Mode='供应商' then (select top 1 t_Supplier.你的列 from t_Supplier) else (select top 1 t_Client.你的列 from t_Client) end 此列的别FROM dbo.t_Other AS a LEFT OUTER JOIN dbo.t_BillType AS b ON a.F_Type = b.F_Name LEFT OUTER JOIN dbo.t_Emp AS c ON a.F_EmpID = c.F_ID
------解决方案--------------------
case when 没你那样的用法。
select *
FROM dbo.t_Other AS a LEFT OUTER JOIN
dbo.t_BillType AS b ON a.F_Type = b.F_Name LEFT OUTER JOIN
dbo.t_Emp AS c ON a.F_EmpID = c.F_ID
LEFT OUTER JOIN t_Supplier d ON a.F_UnitID = d.F_ID and b.F_Mode='供应商'
LEFT OUTER JOIN t_Client e ON a.F_UnitID = e.F_ID and b.F_Mode='客户'
LEFT OUTER JOIN t_Dept f ON a.F_UnitID = f.F_ID and b.F_Mode not in('客户','供应商')
结果列自已打出来。
------解决方案--------------------
CASE WHEN 的结果是个值，不是结果集，不能进行关联。楼主最好把case when 放到select后面或者group by后面实现想要的效果，比如类似下面的写法
- SQL code
select a.*, case when b.F_Mode='供应商' then (select top 1 t_Supplier.你的列 from t_Supplier) else (select top 1 t_Client.你的列 from t_Client) end 此列的别FROM dbo.t_Other AS a LEFT OUTER JOIN dbo.t_BillType AS b ON a.F_Type = b.F_Name LEFT OUTER JOIN dbo.t_Emp AS c ON a.F_EmpID = c.F_ID