How to delete duplicate records from a table?(for suppose in
a table we have 1000 Records in that we have 200 duplicate
Records , so ,how to findout that duplicate Records , how to
delete those Records and arranged into sequence order? one
more thing that there is no primary key at all)
Answers were Sorted based on User's Feedback
Answer / sneha
select distinct * from table into new_table;
delete table;
select * from new_table into table;
Is This Answer Correct ? | 8 Yes | 6 No |
Answer / cp
DELETE FROM emp WHERE ROWID NOT IN(SELECT MAX(ROWID) FROM
emp GROUP BY empno)
Is This Answer Correct ? | 2 Yes | 3 No |
Answer / smitha
;with empctc(empid,ename,sal,deptid,ranking)
as
(Select empid,ename,sal,deptid,ranking=Dense_rank() over (
partition by empid,ename,sal,deptid order by NEWID() asc)
from emp
)
delete * from empctc where ranking>1
Is This Answer Correct ? | 2 Yes | 5 No |
Answer / sirisha
with numbered as(select rowno = row_number() over(partition
by empid order by empid),empname from employee)delete from
numbered where rowno > 1
Is This Answer Correct ? | 1 Yes | 6 No |
Answer / pooja narang
We will get the duplicate records and insert them into a
new temp table by using below query:
select * into tmp_Employee
from Employee
having count(distinct *) > 1
Now delete the duplicate records from Employee table:
delete from Employee
having count(distinct *) > 1
Now insert the records from tmp_Employee to Employee table:
insert into Employee
select * from tmp_employee
drop table tmp_employee
Is This Answer Correct ? | 4 Yes | 15 No |
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