how do you count the duplicate records in a table
Answers were Sorted based on User's Feedback
Answer / priya
select coloumn_name ,count(*) from table_name
group by coloumn_name
having count(*) > 1;
| Is This Answer Correct ? | 35 Yes | 0 No |
Answer / babu
Try this,
select col1,count(col1) from tab1
group by col1 having count(col1)>1;
If you want to delete these duplicate entries, use:
delete from tab1 where col1 in (select a.col1 from
(select col1,count(col1) from tab1
group by col1 having count(col1)>1) a);
| Is This Answer Correct ? | 18 Yes | 1 No |
Answer / purushotham
select column,count(1) from a
group by column
having count(1)>1;
| Is This Answer Correct ? | 7 Yes | 1 No |
Answer / dev
Hi,
There are many ways to do it.
One of that is ,
select count(0) from tab1 a
where a.rowid > any (select b.rowid from tab1 b where
a.col1 =b.col1);
| Is This Answer Correct ? | 6 Yes | 4 No |
Answer / akki julak
select count(empno)-count(distinct(empno)) from emp;
| Is This Answer Correct ? | 3 Yes | 2 No |
Answer / ajmal khan
There are many way to count the duplicate row in a table
select count(column_name)-count(distinct(column_name)) from
table_name;
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / suresh a
select sum(count(col1) -1) from emp
group by col1 having count(col1) > 1
| Is This Answer Correct ? | 2 Yes | 2 No |
Answer / shalu
select count(*) from table_name group by column1,column2...
having count(*) > 1
| Is This Answer Correct ? | 2 Yes | 2 No |
Answer / sravan
Hi here is another way to solve this
SELECT NAME, COUNT(NAME) FROM TABLE_NAME
WHERE NAME IN (SELECT NAME FROM TABLE_NAME
GROUP BY NAME
HAVING COUNT(NAME)>1)
GROUP BY NAME;
thanks
| Is This Answer Correct ? | 0 Yes | 0 No |
Answer / satheesh
SELECT COUNT(*)
FROM TABLE A
WHERE ROWID NOT IN (SELECT MAX(ROWID)
FROM TABLE B
WHERE A.COL1 = B.COL1);--UNIQUE COLUMN
| Is This Answer Correct ? | 0 Yes | 0 No |
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