Deleting duplicate rows with condition(Using SQL and LINQ)

Question

1.00/5 (1 vote)

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SQL

LINQ

I have a table with 5 columns

ID

CPT4

CPT4Mod

ItemCharge

Eff_Date

Deletion Condition:

When rows exists with duplicate CPT4 and CPT4Mod field values but different ItemCharge and Eff_Date values, exclude all but the most recent Eff_Date records.

I need a query which can achieve this in two scenarios.

1. When CPT4Mod is given by the user.
2. When CPT4Mod is not given by the user.

Later I need to achieve the same using LINQ.

Posted 21-Dec-14 6:36am

Arya440

Updated 21-Dec-14 16:37pm

George Jonsson

v5

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Comments

Maciej Los 21-Dec-14 13:34pm

More details needed. Post sample data and expected result.
[EDIT]
Unclear... still

ArunRajendra 21-Dec-14 23:02pm

Post what have you tried?

Sinisa Hajnal 22-Dec-14 3:24am

I don't know LINQ enough for this. But in SQL version. Create a table with the dates you have to retain (use MAX (Eff_Date) - most recent). Then use minus operator to delete everything except those you already selected.

Sinisa Hajnal 22-Dec-14 6:26am

I found LINQ solution (three different ways) easily - you didn't do anything to look for this before asking. Vote 1.

Praveen Kumar Upadhyay 22-Dec-14 7:09am

Delete Condition is not clear. Please post some sample data and expected output.

3 solutions

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Arya440 · Answer 1 · 2014-12-22T03:22:00

Solution 1

SQL

SELECT *
FROM
(
SELECT ROW_NUMBER() OVER (PARTITION BY CPT4, CPT4MOD, ITEMCHARGE ORDER BY EFF_DATE DESC) AS RowNo
    , *
FROM #table
) AS T
WHERE T.RowNo = 1

Posted 22-Dec-14 3:22am

Arya440

Comments

PIEBALDconsult 22-Dec-14 10:00am

Don't answer your own question. Just use Improve question to add it to the question.

iamvinod34 · Answer 2 · 2014-12-22T04:05:00

Solution 2

SQL

WITH CTE AS(
       SELECT COL1, COL2, COL3,COL4,
RN = ROW_NUMBER()OVER(PARTITION BY COL1 ORDER BY COL1)
   FROM TABLE NAME
)
DELETE FROM CTE WHERE RN > 1

Posted 22-Dec-14 4:05am

iamvinod34

User 11060979 · Answer 3 · 2014-12-22T05:37:00

Just on the fly and of course not tested and most probably performance problems:

SQL

DELETE FROM MyTable MyTable_Delete
WHERE EXISTS (SELECT MyTable_Cond.ID FROM MyTable MyTable_Cond
               WHERE MyTable_Cond.CPT4 = MyTable_Delete.CPT4
                 AND MyTable_Cond.CPT4Mod = MyTable_Delete.CPT4Mod
                 AND MyTable_Cond.ItemCharge <> MyTable_Delete.ItemCharge
                 AND MyTable_Cond.Eff_Date <> MyTable_Delete.Eff_Date)
            AND MyTable_Delete.Eff_Date < (SELECT MAX(MyTable_Latest.Eff_Date)
                                             FROM MyTable MyTable_Latest
                                             WHERE MyTable_Latest.CPT4 = MyTable_Delete.CPT4
                                             AND MyTable_Latest.CPT4Mod = MyTable_Delete.CPT4Mod
                                             AND MyTable_Latest.ItemCharge <> MyTable_Delete.ItemCharge
                                             AND MyTable_Latest.Eff_Date <> MyTable_Delete.Eff_Date)