SQL Query - Using Information From One Inquiry In Another - sql

Question

Here is my query. I removed the table names along with other things I am selecting just to make it easier to read.
Select
b.Key1,
b.Key2
From
b
left join c
on c.MailingKey = b.MailingKey
left join d
on d.OrderLineKey = c.OrderLineKey
left join e
on e.ShipKey = d.ShipKey
left join g
on d.ShipKey5 = g.ShipKey5
left join a
on a.DocKey = b.OrderKey
left join f
on f.pMethKey = b.MethKey
I need to use Key1 and Key2 that I select in another query to get more information about that key (location, ID, etc.) from another table. I am thinking I will need to make 2 loops within this original query and join them all up. So something like this:
Select b.Key1, b.Key2, h.*, i.*
From b left join
c on c.MailingKey = b.MailingKey left join
d on d.OrderLineKey = c.OrderLineKey left join
e on e.ShipKey = d.ShipKey left join
g on d.ShipKey5 = g.ShipKey5 left join
a on a.DocKey = b.OrderKey left join
f on f.pMethKey = b.MethKey left join
(
Select*
From table l
Where ID = b.Key1
) h left join (
Select*
From table l
Where ID = b.Key2
) i
I am just not sure how to write equal to b.Key1 and b.Key2.
I am using Microsoft Sql Server Management.

Answer 1

Common table expression:
with cte as (
Select b.Key1, b.Key2
From b left join
c on c.MailingKey = b.MailingKey left join
d on d.OrderLineKey = c.OrderLineKey left join
e on e.ShipKey = d.ShipKey left join
g on d.ShipKey5 = g.ShipKey5 left join
a on a.DocKey = b.OrderKey left join
f on f.pMethKey = b.MethKey)
Select * from CTE
INNER JOIN othertable o
on b.key1=o.key1
and b.key2=o.key2
or do you mean...
Inline view:
Select *
from otherTable
INNER JOIN (
Select b.Key1, b.Key2
From b left join
c on c.MailingKey = b.MailingKey left join
d on d.OrderLineKey = c.OrderLineKey left join
e on e.ShipKey = d.ShipKey left join
g on d.ShipKey5 = g.ShipKey5 left join
a on a.DocKey = b.OrderKey left join
f on f.pMethKey = b.MethKey) CTE
on b.key1=o.key1
and b.key2=o.key2
Or do you mean.... something else?
Perhaps:... using an OR statement...
Select *
from otherTable o
INNER JOIN (
Select b.Key1, b.Key2
From b left join
c on c.MailingKey = b.MailingKey left join
d on d.OrderLineKey = c.OrderLineKey left join
e on e.ShipKey = d.ShipKey left join
g on d.ShipKey5 = g.ShipKey5 left join
a on a.DocKey = b.OrderKey left join
f on f.pMethKey = b.MethKey) CTE
on o.key1=cte.key1
OR o.key2=cte.key2
or maybe... an in statement (within this set)
Select *
from otherTable o
INNER JOIN (
Select b.Key1, b.Key2
From b left join
c on c.MailingKey = b.MailingKey left join
d on d.OrderLineKey = c.OrderLineKey left join
e on e.ShipKey = d.ShipKey left join
g on d.ShipKey5 = g.ShipKey5 left join
a on a.DocKey = b.OrderKey left join
f on f.pMethKey = b.MethKey) CTE
on o.key1 IN (cte.key1, cte.key2)