多个SQL WITH子句-为什么不呢？

Question

I had 2 separate queries.

Query 1:

With A as (Select P,Q,R from X union all Select P,Q,R from Y)
Insert into File1
Select * from A

Query 2:

With B as (Select S,T,U from Z)
Insert into File2
Select * from B

I realised that,logically, I always need to produce File1 and File2 together, so I decided to just merge the 2 queries into one Stored Procedure. However, when I tried to do it, I hit this problem where it's only possible to have one WITH clause in a query.

So, I found a few questions in SO where people explained that you just use a comma and have a separate WITH clause (albeit, without the WITH) but this wouldn't work in any form for my example.

It wasn't a problem - I've easily worked around it by using temporary tables etc. But I'm really intrigued as to why I can't have two entirely unrelated WITH clauses in the same Proc?

Can anyone explain please?

Answer 1

You should be able to have 2 WITH clauses, you just need a semicolon after the first one.

With A as (Select P,Q,R from X union all Select P,Q,R from Y)
Insert into File1
Select * from A;


With B as (Select S,T,U from Z)
Insert into File2
Select * from B

This is the error you would get from SQL if you are trying to do two without semicolon:

Msg 336, Level 15, State 1, Line 6
Incorrect syntax near 'B'. If this is intended to be a common table expression, you need to explicitly terminate the previous statement with a semi-colon.