How to query for duplicates in multiple fields in SQL Server?

4 months ago

1 minute

In SQL Server, you can use the GROUP BY clause and the HAVING clause to perform distinct queries on multiple fields.

Suppose there is a table named “table_name” with several fields such as “column1,” “column2,” and “column3.” To perform a query to remove duplicates from these fields, you can use the following syntax:

SELECT column1, column2, column3
FROM table_name
GROUP BY column1, column2, column3
HAVING COUNT(*) > 1

This will return all records that are duplicated in these three fields. If you only want to return the count of duplicate records, you can use the following syntax:

SELECT COUNT(*) AS duplicate_count
FROM (
    SELECT column1, column2, column3
    FROM table_name
    GROUP BY column1, column2, column3
    HAVING COUNT(*) > 1
) AS duplicates

This will return the number of duplicate records.