Introduction:
In this article I will explain how to delete or remove duplicate records or rows from a datatable in SQL server.
In this article I will explain how to delete or remove duplicate records or rows from a datatable in SQL server.
Description:
I will explain
how to delete duplicate records from a datatable in SQL server. During work
with one application I got requirement like get the unique records from
datatable in sql server. Actually our datatable does not contain any primary
key column because of that it contains duplicate records that would be like
this
Actually
above table does not contain any primary key column because of that same type
of records exist.
Now
I want to get duplicate records from datatable for that we need to write query
like this
WITH tempTable as
(
SELECT ROW_NUMBER() Over(PARTITION BY Name,Position ORDER BY Name) As RowNumber,* FROM EmployeData
)
SELECT * FROM tempTable
|
Once
we run above query we will get data like this
If
you observe above table I added another column RowNumber this column is used to know which record contains
duplicate values based on rows with RowNumber
greater than 1.
Now
we want to get the records which contains unique value from datatable for that
we need to write the query like this
WITH tempTable as
(
SELECT ROW_NUMBER() Over(PARTITION BY Name,Position ORDER BY Name) As RowNumber,* FROM EmployeData
)
DELETE FROM
tempTable where RowNumber >1
SELECT * FROM EmployeData order
by Id asc
|
Once
we run above query all duplicate records will delete from our table and that
would be like this
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