SQLServer EXISTS CLAUSE

Get all customers with a least one order

SELECT * FROM Customer WHERE EXISTS (
 SELECT * FROM Order WHERE Order.CustomerId=Customer.Id
)

Get all customers with no order

SELECT * FROM Customer WHERE NOT EXISTS (
 SELECT * FROM Order WHERE Order.CustomerId = Customer.Id
)

Purpose

EXISTS, IN and JOIN could sometime be used for the same result, however, they are not equals :

.EXISTS should be used to check if a value exist in another table

.IN should be used for static list

.JOIN should be used to retrieve data from other(s) table(s)

Conclusion

In this page (written and validated by A. Gawali) you learned about SQLServer EXISTS CLAUSE . What's Next? If you are interested in completing SQLServer tutorial, your next topic will be learning about: SQLServer JOIN.

Incorrect info or code snippet? We take very seriously the accuracy of the information provided on our website. We also make sure to test all snippets and examples provided for each section. If you find any incorrect information, please send us an email about the issue: mockstacks@gmail.com.

Share On:

Mockstacks was launched to help beginners learn programming languages; the site is optimized with no Ads as, Ads might slow down the performance. We also don't track any personal information; we also don't collect any kind of data unless the user provided us a corrected information. Almost all examples have been tested. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. By using Mockstacks.com, you agree to have read and accepted our terms of use, cookies and privacy policy.