---
title: "Explain the concept of \"unique key violation\" error."  
description: "Explain the concept of \"unique key violation\" error."  
author: "Sandra Emily"  
published: 2023-08-20  
updated: 2023-08-21  
canonical: https://www.mindstick.com/forum/159605/explain-the-concept-of-unique-key-violation-error  
category: "mssql server"  
tags: ["sql server", "sql", "error"]  
reading_time: 2 minutes  

---

# Explain the concept of "unique key violation" error.

[Explain the concept](https://www.mindstick.com/forum/160501/explain-the-concept-of-a-servlet-context) of "[unique key](https://answers.mindstick.com/qa/116303/explain-database-primary-key-vs-unique-key) violation" error.

## Replies

### Reply by Aryan Kumar

A [unique](https://www.mindstick.com/blog/12870/how-to-be-unique-in-business) key violation error occurs when an attempt is made to insert a new record into a table that has a unique key on one or more columns, and the value or values being inserted into the unique key field or fields already exists in the table.

Unique keys are used to ensure that each record in a table has a unique value for the specified field or fields. This helps to prevent duplicate data and to make it easier to find and retrieve records.

When a unique key violation error occurs, the database will not insert the new record and will return an error message. The error message will typically include the following information:

- The table name
- The name of the unique key
- The value that caused the error

To resolve a unique key violation error, you need to change the value of the field or fields that are causing the error so that they are unique. You can also delete the existing record that has the same value.

Here are some examples of unique key violation errors:

- Trying to insert a new customer record with the same email address as an existing customer record.
- Trying to insert a new product record with the same SKU as an existing product record.
- Trying to update a customer record with a new email address that is already in use by another customer.

If you are not sure why you are getting a unique key violation error, you should consult with a database expert to help you troubleshoot the issue.

Here are some tips for avoiding unique key violation errors:

- Make sure that the values you are inserting into the unique key fields are unique.
- Use a database tool to check for duplicate values before you insert a new record.
- Use a database trigger to prevent duplicate values from being inserted.

By following these tips, you can help to prevent unique key violation errors and keep your database data accurate and consistent.


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Original Source: https://www.mindstick.com/forum/159605/explain-the-concept-of-unique-key-violation-error

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