duplicate data

Technical Article

Listing Duplicate Values by Group

  • Article

Without question, one of the most common tasks performed by Database Administrators (DBAs) is identifying and weeding out duplicate values in tables. Despite the inordinate number of queries written by other DBAs to locate duplicate values in their database tables, the real challenge is in locating a useable SQL statement to go by. Rob Gravelle presents a few solutions that will save you some time down the road.

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2016-12-15

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Question of the Day

The Empty Aggregate

I have this table in a SQL Server 2025 database:

CREATE TABLE [dbo].[CustomerOrder]
(
[OrderID] [int] NULL,
[CustomerID] [int] NULL,
[total] [money] NULL
) ON [PRIMARY]
GO
What is returned from this code? (answers are for the sum and then the count)
SELECT SUM(total) AS sum,
       COUNT(total) AS count
FROM dbo.CustomerOrder;



See possible answers