SQL联接在哪里条件

Question

How do I join these two tables

select m.caseno,
sum(m.BalanceAmount) GOVT from TABLE1 m
inner join TABLE2 g on m.Code = g.Code
where g.alpha in ('a','b','c') 
group by m.caseno

OUTPUT CASE | GOVT

select m.caseno,
sum(m.BalanceAmount) MIF from TABLE1 m
inner join TABLE2 g on m.Code = g.Code
where g.alpha in ('d','e')
group by m.caseno

OUTPUT CASE | MIF

I want them to join in a single query CASE | GOVT | MIF

Answer 1

If you don't want to touch the existing queries, you can do a FULL OUTER JOIN with them:

select
  coalesce(a.caseno, b.caseno) as caseno,
  a.govt,
  b.mif
from ( -- first query
  select m.caseno,
  sum(m.BalanceAmount) GOVT from TABLE1 m
  inner join TABLE2 g on m.Code = g.Code
  where g.alpha in ('a','b','c') 
  group by m.caseno
) a
full outer join ( -- second query
  select m.caseno,
  sum(m.BalanceAmount) MIF from TABLE1 m
  inner join TABLE2 g on m.Code = g.Code
  where g.alpha in ('d','e')
  group by m.caseno
) b on a.caseno = b.caseno

The FULL OUTER JOIN is necessary -- as well as the COALESCE() -- to join non-matching rows that may show up in either queries.

Answer 2

use case when to show as 2 columns.

select m.caseno,
sum(case when g.alpha in ('d','e') then m.BalanceAmount else 0 end)  MIF ,
sum(case when g.alpha in ('a','b','c') then m.BalanceAmount else 0 end)  GOVT 
from TABLE1 m
inner join TABLE2 g on m.Code = g.Code
where g.alpha in ('a','b','c','d','e')
group by m.caseno

Answer 3

you have to perform a full outer join i think. try this.

SELECT *
FROM (
  select m.caseno,
    sum(m.BalanceAmount) GOVT from TABLE1 m
  inner join TABLE2 g on m.Code = g.Code
  where g.alpha in ('a','b','c') 
  group by m.caseno
) AS tab1
FULL OUTER JOIN (
  select m.caseno,
    sum(m.BalanceAmount) MIF from TABLE1 m
  inner join TABLE2 g on m.Code = g.Code
  where g.alpha in ('d','e')
  group by m.caseno
) AS tab2 
  ON tab2.caseno = tab1.caseno