3 tables 2 sums query?

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October 6th, 2009, 04:49 PM

jperry

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3 tables 2 sums query?

Hi All,

My brain is hurting..Please help!!!

I have 3 tables:

Table A
ID
Username

Table B
ParentID
SomeNumber

Table C
ParentID
SomeNumber

I need something like this (The totals of SomeNumber from both tables B and C for a given user in A):
select a.username, sum(b.SomeNumber), sum(c.SomeNumber) from A, B, C where A.ID = B.ParentID and A.ID = C.ParentID group by a.ID

Any help would be appreciated!!!! Thanks!!

October 6th, 2009, 05:05 PM

MrFujin

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do you get any errors message?
wrong result?

you have to give some more information about you problem.

what if you group by a.username instead of group by a.ID?

October 6th, 2009, 06:08 PM

jperry

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Quote:

Originally Posted by MrFujin

do you get any errors message?
wrong result?

you have to give some more information about you problem.

what if you group by a.username instead of group by a.ID?

When I use a.username the query executes but there are no results. I know for sure there is data present.

October 6th, 2009, 06:11 PM

jperry

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Quote:

Originally Posted by jperry

When I use a.username the query executes but there are no results. I know for sure there is data present.

SNAP!!! If either of the tables is empty, I get no results. I need to outer join the two child tables right?

What does that look like?

October 7th, 2009, 04:19 AM

swampBoogie

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Code:

select username, 
       (select sum(someNumber)
          from b
         where b.parentid = a.id),
       (select sum(SomeNumber) 
          from c
         where c.parentid = a.id)
  from A

October 7th, 2009, 09:53 AM

jperry

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Quote:

Originally Posted by swampBoogie

Code:

select username, 
       (select sum(someNumber)
          from b
         where b.parentid = a.id),
       (select sum(SomeNumber) 
          from c
         where c.parentid = a.id)
  from A

Thanks guys!!

Here's what I ended up with. Any real difference? Performance?

select a.username, sum(b.SomeNumber), sum(c.SomeNumber)
from a
left outer join b on (a.id = b.parentid)
left outer join c on (a.id = c.parentid)
group by username

October 7th, 2009, 10:16 AM

swampBoogie

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The queries will give different results in some cases.

You can test with this data

Code:

create table a(id int,username varchar(20));
insert into a values(1,'swampBoogie');

create table b(parentId int,somenumber int);
insert into b values(1,47);
insert into b values(1,11);

create table c(parentId int,somenumber int);
insert into c values(1,4711);

October 14th, 2009, 01:26 PM

jperry

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Quote:

Originally Posted by swampBoogie

The queries will give different results in some cases.

You can test with this data

Code:

create table a(id int,username varchar(20));
insert into a values(1,'swampBoogie');

create table b(parentId int,somenumber int);
insert into b values(1,47);
insert into b values(1,11);

create table c(parentId int,somenumber int);
insert into c values(1,4711);

Welp, I just got back to this and you're RIGHT! But now I have another problem....

I need want the totals by username (i.e. group by username) but I'm getting multiple records back for a given user.

I've tried a couple of different ways to group things but nothing works right.

Thoughts?

October 16th, 2009, 04:03 AM

swampBoogie

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I'm not sure I understand what you mean, but this would get the total for each user

Code:

select username, 
       coalesce((select sum(someNumber)
          from b
         where b.parentid = a.id),0) +
       coalesce((select sum(SomeNumber) 
          from c
         where c.parentid = a.id),0)
  from a

If this is not what you need, give some sample data and the expected result.

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