Embedded SQL / Count / GroupBy?

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Hi All,

looking for help to put together some sub-select SQL code.

Sample table data:

VB

-------------------------
RecID | GroupID | User  |
-------------------------
  1   |    1    | John  |
  2   |    1    | Mary  |
  3   |    1    | Fred  |
  4   |    2    | Joe   |
  5   |    2    | Mary  |
  6   |    3    | Fred  |
  7   |    3    | John  |
  8   |    3    | Mary  |
  9   |    4    | Tony  |
  10  |    5    | Fred  |
-------------------------

I want to query the count of a particular set of users without knowing the GroupID.
For example, how many times do (John + mary + Fred) appear in a grouping?
(in the sample above, its twice, but in a different order).

I am very rusty but think it should be a "Select count (*) from [select Grouping]
where User in [set?]

Any thoughts on something efficent?

many thanks,

Allen.

Posted 17-May-11 3:44am

DataBytzAI

Updated 17-May-11 4:05am

v2

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Sandeep Mewara 17-May-11 9:58am

(in the sample above, its twice, but in a different order).
I don't see how you got this! :doh:
Unclear...

DataBytzAI 17-May-11 10:07am

Thanks Mewara - I made a mistake in the sample data!! ... well spotted!!

I have fixed it now. In the table there are two sets of GroupID that John + Mary + Fred appear in,
namely GroupID 1 and GroupID 3. I am trying to put together an SQL statement that will tell me the Count of the groups they appear in, ie: 2

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DataBytzAI · Answer 1 · 2011-05-17T04:19:00

solved by Kent on MSDN

!declare @test table
( recId integer,
GroupId integer,
[User] varchar(9))
insert into @test
select 1 , 1, 'John' union all
select 2 , 1, 'Mary' union all
select 3 , 1, 'Fred' union all
select 4 , 2, 'Joe ' union all
select 5 , 2, 'Mary' union all
select 6 , 3, 'Fred' union all
select 7 , 3, 'John ' union all
select 8 , 3, 'Mary' union all
select 9 , 4, 'Tony' union all
select 10, 5, 'Fred'

select
GroupId
from @test
where [user] in ('John','Mary','Fred')
group by groupId
having count(distinct [user]) = 3

/* -------- Output: --------
GroupId
-----------
1
3

(1 row(s) affected)
*/

select count(*) as Group_Count
from
( select
GroupId
from @test
where [user] in ('John','Mary','Fred')
group by groupId
having count(distinct [user]) = 3
) x

/* -------- Output: --------
Group_Count
-----------
2
*/