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Write a single SQL to delete duplicate records from the a
single table based on a column value. I need only Unique
records at the end of the Query.
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Answer Posted / yuvaevergreen
If atleast one column is distinct, we can delete using
delete statement.
EMPLOYEE TABLE:
EMPNO EMPNAME DEPT
1 YUVA SCI
2 YUVA SCI
DELETE FROM EMPLOYEE WHERE
(EMPNO, EMPNAME,DEPT)
NOT IN
(SELECT EMPNO, EMPNAME,DEPT FROM EMPLOYEE
QUALIFY ROW_NUMBER() OVER
(PARTITION BY EMPNO
ORDER BY EMPNO,EMPNAME,DEPT ASC ) = 1 );
If all the columns are same, then create and drop would be used.
EMPNO EMPNAME DEPT
1 YUVA SCI
1 YUVA SCI
CREATE EMP_NEW AS EMP WITH NO DATA;
INSERT INTO EMP_NEW
SELECT EMPNO, EMPNAME,DEPT FROM EMPLOYEE
QUALIFY ROW_NUMBER() OVER
(PARTITION BY EMPNO, EMPNAME,DEPT
ORDER BY EMPNO,EMPNAME,DEPT ASC ) = 1;
DROP TABLE EMP;
RENAME EMP_NEW TO EMP;
| Is This Answer Correct ? | 9 Yes | 6 No |
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