Delete duplicate rows from a table without primary key by
using a single query
Table Employee
empname salary
A 200
B 300
A 200
C 400
D 500
D 500
Output should be
A 200
B 300
C 400
D 500
Answer Posted / pradeep
DECLARE @TEMP_TABLE TABLE (EMPNAME VARCHAR(10),SALARY
VARCHAR(10))
INSERT INTO @TEMP_TABLE (EMPNAME ,SALARY )
SELECT 'A','200' UNION ALL
SELECT 'B','300' UNION ALL
SELECT 'C','400' UNION ALL
SELECT 'A','200' UNION ALL
SELECT 'A','200' UNION ALL
SELECT 'D','500' UNION ALL
SELECT 'D','500' UNION ALL
SELECT 'B','300'
/* TABLE RAW DATA */
SELECT * FROM @TEMP_TABLE
SELECT * FROM @TEMP_TABLE AS A
WHERE (SELECT COUNT(*) FROM @TEMP_TABLE AS B WHERE
A.EMPNAME=B.EMPNAME AND A.SALARY=B.SALARY) > 1
/* OUTPUT SHOULD BE */
SELECT DISTINCT * FROM @TEMP_TABLE
/* DELETE DUPLICATE/TRIPLICATE.... RECORDS */
SET ROWCOUNT 1
DELETE @TEMP_TABLE FROM @TEMP_TABLE AS A
WHERE (SELECT COUNT(*) FROM @TEMP_TABLE AS B WHERE
A.EMPNAME=B.EMPNAME AND A.SALARY=B.SALARY) > 1
WHILE @@ROWCOUNT > 0
DELETE @TEMP_TABLE FROM @TEMP_TABLE AS A
WHERE (SELECT COUNT(*) FROM @TEMP_TABLE AS B WHERE
A.EMPNAME=B.EMPNAME AND A.SALARY=B.SALARY) > 1
SET ROWCOUNT 0
/**********************************************/
/* EXPECTED OUTPUT TABLE */
SELECT * FROM @TEMP_TABLE
Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
What is temporal data type?
Which tcp/ip port does the sql server run on? How can it be changed?
what are the core components of SSRS?
What is filestream?
what are constraints? : Sql server database administration
How to use group functions in the select clause in ms sql server?
How do you run a trace?
What is a transaction and why is it important?
What is sql server english query?
What do you understand by mirroring?
Mention the command used to rename the database.
You want to implement the one-to-one relationship while designing tables. How would you do it?
What is query optimizer in sql server?
What is the sql profiler?
what is the main function of a query parameter?