how to self join a table? - sql

Question

After Updating query i got following output with this query
i am writing following query to put two sets of records next to each other.
WITH cte AS
(SELECT SubSubsidaryAccountCode,
sum(Debit) AS debit,
sum(Credit) AS credit,
ROW_NUMBER() over (PARTITION BY SubSubsidaryAccountCode
ORDER BY SubSubsidaryAccountCode) AS RN
FROM TBLLedgerLevel4
WHERE SubSubsidaryAccountCode LIKE '4%'
OR SubSubsidaryAccountCode LIKE '5%'
GROUP BY SubSubsidaryAccountCode ),
cte2 AS
(SELECT *
FROM TBLLevel4)
SELECT a.SubSubsidaryAccountCode ,
c.SubSubsidaryAccountName AS RevenuName ,
sum(a.Debit) AS debit ,
b.SubSubsidaryAccountCode AS SubsidaryAccount2 ,
d.SubSubsidaryAccountName AS ExpenseName ,
sum(b.Credit) AS credit
FROM cte a
JOIN cte2 c ON a.SubSubsidaryAccountCode = c.SubSubsidaryAccountCode
FULL JOIN cte b ON a.RN = b.RN
JOIN cte2 d ON b.SubSubsidaryAccountCode=d.SubSubsidaryAccountCode
WHERE a.SubSubsidaryAccountCode LIKE '4%'
AND b.SubSubsidaryAccountCode LIKE '5%'
GROUP BY a.SubSubsidaryAccountCode,
b.SubSubsidaryAccountCode,
c.SubSubsidaryAccountName,
d.SubSubsidaryAccountName
Output:
SubSubsidaryAccountCode RevenuName debit SubsidaryAccount2 ExpenseName credit
4-106-1001-10026 Cash Sale 52889 5-105-1005-10011 Rf Battles 18091289
4-108-1012-10037 New Sale1 1000 5-105-1005-10011 Rf Battles 18091289
The above output contains records against two Accounting codes that starts with 4 and 5 .Now the records against accounting code that are starting with accounting code like 4 are populated and are according to desired results but the 2nd row of record starting with accounting code 5 does not have any value and must have null value in it.Please help me out to solve this problem.

Answer 1

Your sample makes it seem like it's arbitrary which ones are populated and which are NULL, like you just want to put two sets of records next to each other. You could do that by adding a ROW_NUMBER() and using that in a LEFT JOIN:
;with cte AS (SELECT *,ROW_NUMBER() OVER(PARTITION BY MainAccountID ORDER BY LedgerDate) AS RN
FROM TBLLedgerLevel1
)
SELECT a.LedgerDate
, a.MainAccountId
, a.VoucherCode
, a.Debit
, b.LedgerDate AS Date2
, b.MainAccountId AS MainAccount2
, b.VoucherCode AS VoucherCode2
, b.Credit
FROM cte a
LEFT JOIN cte b
ON a.RN = b.RN
and b.MainAccountId='5'
WHERE a.MainAccountId='4'
If there could be more MainAccountId='5' records than MainAccountId='4' you'd probably want a FULL JOIN and could use COALESCE() to choose which field to display. Also, making use of aliases cleans up code significantly in my opinion.
Update: Not sure exactly on this, but to add the name you'll need to add a JOIN to TBLLevel1, something like:
;with cte AS (SELECT *,ROW_NUMBER() OVER(PARTITION BY MainAccountID ORDER BY LedgerDate) AS RN
FROM TBLLedgerLevel1
)
SELECT a.LedgerDate
, a.MainAccountId
, a.VoucherCode
, a.Debit
, b.LedgerDate AS Date2
, b.MainAccountId AS MainAccount2
, b.VoucherCode AS VoucherCode2
, b.Credit
, c.MainAccountName
FROM cte a
JOIN TBLLevel1 c
ON a.MainAccountID = c.ID
LEFT JOIN cte b
ON a.RN = b.RN
and b.MainAccountId='5'
WHERE a.MainAccountId='4'
If there's more than 1 record per MainAccountId in the TBLLevel1 table you'll need to add criteria to the JOIN to make sure only the proper value is included.