Is it possible to group unlike items and count them together? - sql

Question

Given the following table:
Chain Name
123 Company 1
124 Other Company 1
123 Whatever Company
125 This One
126 That One
125 Another One
127 Last One
I get the following results when I do a Count on the Chain column:
123 2
124 1
125 2
126 1
127 1
Is it possible to group Chain 123 and 124 so they're counted together? Also group 125 and 126? The modified results would look like this:
123/124 3
125/126 3
127 1
My SQL looks like this:
SELECT Table1.Chain, Count(*) as [Count]
FROM Table1 LEFT JOIN Table2 on Table1.Chain = Table2.Chain
WHERE (((Table1.Chain) IN (Table2.Chain)))
GROUP BY Table1.Chain
ORDER BY Table1.Chain;
Thank you!

Answer 1

Depending upon your needs, this might be a bit of a hack, but I would probably add a table to store the Chain and ChainGroup that you are seeking. Something like this:
Chain ChainGroup
123 123/124
124 123/124
125 125/126
126 125/126
127 127/128
Then, in the query, I would join to this table and instead of grouping by Chain I would group by ChainGroup.
I would prefer this over something like a nested IIF statement as those get pretty difficult to debug, and odds are you'll have additional groupings in the future which would be trivial to add to the table and have the new grouping automatically appear in the query.

Answer 2

yes, you can:
SELECT min(Table1.Chain) & '/' & max(Table1.Chain) as chain, Count(*) as [Count]
FROM Table1 LEFT JOIN Table2 on Table1.Chain = Table2.Chain
WHERE (((Table1.Chain) IN (Table2.Chain)))
GROUP BY int((Table1.Chain-1)/2)
ORDER BY min(Table1.Chain);

Answer 3

You can use a nested Iif statement. Hopefully I've got all my parentheses right below! :-)
SELECT Iif(Table1.Chain="123", "123/124",
Iif(Table1.Chain="124", "123/124",
Iif(Table1.Chain="125", "125/126",
Iif(Table1.Chain="126", "125/126", Table1.Chain)))) as [Chain]
, Count(*) as [Count]
FROM Table1 LEFT JOIN Table2 on Table1.Chain = Table2.Chain
WHERE (((Table1.Chain) IN (Table2.Chain)))
GROUP BY Iif(Table1.Chain="123", "123/124",
Iif(Table1.Chain="124", "123/124",
Iif(Table1.Chain="125", "125/126",
Iif(Table1.Chain="126", "125/126", Table1.Chain))))
ORDER BY Table1.Chain;
You could also move the case statement into a subquery in your from clause or a common table expression if you don't want to write it twice in your query.

Answer 4

consider something like:
SELECT
chain_group, COUNT(*) FROM (
SELECT
Table1.Chain,
switch(Table1.Chain IN("123","124"), "123/124",
Table1.Chain IN("125","126"),"125/126",
Table1.Chain) AS chain_group
FROM
Table1 INNER JOIN
Table2 ON
Table1.Chain = Table2.Chain) t
GROUP BY chain_group
ORDER BY chain_group

Answer 5

You can see the below example
----- Make main Table
CREATE TABLE #test
( id int , Name varchar(100))
INSERT #test(id,Name)
values (123,'Company 1'),
(124,'Other Company 1'),
(123, 'Whatever Company'),
(125, 'This One'),
(126 , 'That One'),
(125, 'Another One'),
(127, 'Last One')
CREATE TABLE #temp
(rowID INT IDENTITY(1,1) , ID INT ,cnt INT )
CREATE TABLE #tempResult
(ID VARCHAR(20) ,cnt INT )
INSERT INTO #temp(ID,cnt)
SELECT ID ,COUNT(1) cnt FROM #test GROUP BY ID
DECLARE #rowCnt INT , #TotalCnt INT , #even INT , #odd INT ,
#idNum VARCHAR(20) , #valueCnt INT , #inStart INT = 1
SET #rowCnt = 1
SET #even = 1
SET #odd = 2
SELECT #TotalCnt = COUNT(1) FROM #temp
WHILE #rowCnt <= #TotalCnt
BEGIN
SET #inStart = 1
SET #odd = #rowCnt
SET #even = #rowCnt + 1
SET #idNum = ''
SET #valueCnt = 0
WHILE #inStart <= 2
BEGIN
IF #inStart = 1
Begin
SELECT #idNum = Convert(VARCHAR(5),ID) , #valueCnt = cnt
FROM #temp WHERE rowID = #odd
End
ELSE
BEGIN
SELECT #idNum = #idNum + '/' + Convert(VARCHAR(5),ID) , #valueCnt = #valueCnt + cnt
FROM #temp WHERE rowID = #even
END
SET #inStart = #inStart + 1
END
INSERT INTO #tempResult (ID, Cnt)
VALUES (#idNum,#valueCnt)
SET #rowCnt = #rowCnt + 2
END
SELECT *
FROM #tempResult