在Select中使用Alias，然后在连接表时使用它。

Question

I hope someone can help.

I have used an alias as so..

select COALESCE(A1.Date, A2.Date, A3.Date, All.Date) as ADate,
.
.
.
) A2
on ADate.Date = A2.Date

It's giving me an error The multi-part identifier "ADate.Date" could not be bound.

Many thanks

Answer 1

You should use it as

select COALESCE(A1.Date, A2.Date, A3.Date, All.Date) as ADate,
.
.
.
) A2
on COALESCE(A1.Date, A2.Date, A3.Date, All.Date) = A2.Date