Query to find out duplicate records

[Shophia_D]

Hi All,

I am working on very complicate SQL projects. My projects includes more than one table. In which I need to find out any duplication of rows which has same content. According to you which function I will need to use in query to find out the duplicate records in the tables. I would greatly appreciate your any help over this query.

[Praetor]

Hi,

I think you should use the "Having" clause in your SQL query. "Having" clause find out the duplication of the provided table field. Please refer the below example of the "Having clause":

SELECT emailID, COUNT(emailID) AS NumOccurrc
FROM acct GROUP BY emailID
HAVING ( COUNT(emailID) > 1 )

[Katty]

If you want to display the records which is unique among the table, Please use the "Dinstinct" clause of the SQL. This keywords avoids the duplication of the table fields. Suppose there is one field value which is repeated three times in the table, if you use "Dinstinct" clause it will display only one occurrence of that value. See below query:

Select Distinct Name, empID from empl
where
salary>=10000

[kelfro]

Hi ,

I also want the similar SQL query which find out the duplicate records. I have three sql databases for my projects. I don't want any value which is common for all three sql databases.
I have tried to use the "Distinct" and "Having" Clause but it didn't give me the desired output. Please let know the proper executable SQL query for duplicated records . I waiting for reply..

[Zecho]

Following query is useful to find out the duplicates records from the two tables named as "tes" and "dup" . In this example I have used the where concept of the SQL query language:

select d
, count(*)
, min(i) from tes
where
1 < (select count(*)
from tes, dup
where tes.d = dup.d
) group by d

[Reegan]

Hello,

You can try below some SQL queries to find out the duplicate records of the table:

1. select * from lmn group by FieldName HAVING count(distinct FieldName > 0)
   
2. select distinct(FieldName ) from TableName.
   
3. select distinct(Sname ) from TableNamestud.