Left Outer Join in SQL Server 2014 - sql

Question

We are currently upgrading to SQL Server 2014; I have a join that runs fine in SQL Server 2008 R2 but returns duplicates in SQL Server 2014. The issue appears to be with the predicate AND L2.ACCOUNTING_PERIOD = RG.PERIOD_TO for if I change it to anything but 4, I do not get the duplicates. The query is returning those values in Accounting Period 4 twice. This query gets account balances for all the previous Accounting Periods so in this case it returns values for Accounting Periods 0, 1, 2 and 3 correctly but then duplicates the values from Period 4.
SELECT
A.ACCOUNT,
SUM(A.POSTED_TRAN_AMT),
SUM(A.POSTED_BASE_AMT),
SUM(A.POSTED_TOTAL_AMT)
FROM
PS_LEDGER A
LEFT JOIN PS_GL_ACCOUNT_TBL B
ON B.SETID = 'LTSHR'
LEFT OUTER JOIN PS_LEDGER L2
ON A.BUSINESS_UNIT = L2.BUSINESS_UNIT
AND A.LEDGER = L2.LEDGER
AND A.ACCOUNT = L2.ACCOUNT
AND A.ALTACCT = L2.ALTACCT
AND A.DEPTID = L2.DEPTID
AND A.PROJECT_ID = L2.PROJECT_ID
AND A.DATE_CODE = L2.DATE_CODE
AND A.BOOK_CODE = L2.BOOK_CODE
AND A.GL_ADJUST_TYPE = L2.GL_ADJUST_TYPE
AND A.CURRENCY_CD = L2.CURRENCY_CD
AND A.STATISTICS_CODE = L2.STATISTICS_CODE
AND A.FISCAL_YEAR = L2.FISCAL_YEAR
AND A.ACCOUNTING_PERIOD = L2.ACCOUNTING_PERIOD
AND L2.ACCOUNTING_PERIOD = RG.PERIOD_TO
WHERE
A.BUSINESS_UNIT = 'UK001'
AND A.LEDGER = 'LOCAL'
AND A.FISCAL_YEAR = 2015
AND ( (A.ACCOUNTING_PERIOD BETWEEN 1 and 4
AND B.ACCOUNT_TYPE IN ('E','R') )
OR
(A.ACCOUNTING_PERIOD BETWEEN 0 and 4
AND B.ACCOUNT_TYPE IN ('A','L','Q') ) )
AND A.STATISTICS_CODE = ' '
AND A.ACCOUNT = '21101'
AND A.CURRENCY_CD <> ' '
AND A.CURRENCY_CD = 'GBP'
AND B.SETID='LTSHR'
AND B.ACCOUNT=A.ACCOUNT
AND B.SETID = SETID
AND B.EFFDT=(SELECT MAX(EFFDT) FROM PS_GL_ACCOUNT_TBL WHERE SETID='LTSHR' AND WHERE ACCOUNT=B.ACCOUNT AND EFFDT<='2015-01-31 00:00:00.000')
GROUP BY A.ACCOUNT
ORDER BY A.ACCOUNT

Answer 1

I'm inclined to suspect that you have simplified your original query too much to reflect the real problem, but I'm going to answer the question as posed, in light of the comments on it to this point.
Since your query does not in fact select anything derived from table L2, nor do any other predicates rely on anything from that table, the only thing accomplished by (left) joining it is to duplicate rows of the pre-aggregation results where more than one satisfies the join condition for the same L2 row. That seems unlikely to be what you want, especially with that particular join being a self join, so I don't see any reason not to remove it altogether. Dollars to doughnuts, that solves the duplication problem.
I'm also going to suggest removing the correlated subquery in the WHERE clause in favor of joining an inline view, since you already join the base table for the subquery anyway. This particular inline view uses the window function version of MAX() instead of the aggregate function version. Ideally, it would directly select only the rows with the target EFFDT values, but it cannot do so without being rather more complicated, which is exactly what I am trying to avoid. The resulting query therefore filters EFFDT externally, as the original did, but without a correlated subquery.
I furthermore removed a few redundant predicates and rewrote one of the messier ones to a somewhat nicer equivalent. And I reordered the predicates in a way that seems more logical to me.
Additionally, since you are filtering on a specific value of A.ACCOUNT, it is pointless (but not wrong) to GROUP BY or ORDER_BY that column. Accordingly, I have removed those clauses to make the query simpler and clearer.
Here's what I came up with:
SELECT
A.ACCOUNT,
SUM(A.POSTED_TRAN_AMT),
SUM(A.POSTED_BASE_AMT),
SUM(A.POSTED_TOTAL_AMT)
FROM
PS_LEDGER A
INNER JOIN (
SELECT
*,
MAX(EFFDT) OVER (PARTITION BY ACCOUNT) AS MAX_EFFDT
FROM PS_GL_ACCOUNT_TBL
WHERE
EFFDT <= '2015-01-31 00:00:00.000'
AND SETID = 'LTSHR'
) B
ON B.ACCOUNT=A.ACCOUNT
WHERE
A.ACCOUNT = '21101'
AND A.BUSINESS_UNIT = 'UK001'
AND A.LEDGER = 'LOCAL'
AND A.FISCAL_YEAR = 2015
AND A.CURRENCY_CD = 'GBP'
AND A.STATISTICS_CODE = ' '
AND B.EFFDT = B.MAX_EFFDT
AND CASE
WHEN B.ACCOUNT_TYPE IN ('E','R')
THEN A.ACCOUNTING_PERIOD BETWEEN 1 and 4
WHEN B.ACCOUNT_TYPE IN ('A','L','Q')
THEN A.ACCOUNTING_PERIOD BETWEEN 0 and 4
ELSE 0
END