How to Find Duplicate Rows in a SQL Table Based on Multiple Fields (e.g., Email and Name)?

Identifying Duplicate Records in SQL Based on Multiple Fields

Finding duplicates in a SQL table is simple with a single field. However, identifying duplicates across multiple fields, such as email and name, requires a more sophisticated approach. This example demonstrates how to locate duplicate entries based on both email and name.

The solution uses a GROUP BY clause modified to include multiple fields:

SELECT
    name, email, COUNT(*) AS DuplicateCount
FROM
    users
GROUP BY
    name, email
HAVING 
    DuplicateCount > 1;

Grouping by name and email ensures that records with identical email and name combinations are grouped together. The HAVING clause then filters these groups, returning only those with a COUNT(*) (renamed as DuplicateCount for clarity) greater than 1, thus pinpointing the duplicate entries. This effectively identifies rows with duplicate name and email pairs.

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