Duplicates: How to find duplicate field values

Date Revised: August 14 2009

Shows how to use t-sql to count the number of duplicate values in a field. There is another example here which shows the same, only using a cursor.

-- Database to use

USE DatabaseName;

-- The trick is to use GROUP BY - HAVING a count greater than 1

SELECT fieldName,

    COUNT(fieldName) AS NumOccurrences

    FROM dbo.TableName

        GROUP BY fieldName

        HAVING ( COUNT(fieldName) > 1 );