Difference: SQL UNION vs UNION ALL ? UNION and UNION ALL are both used to retrieve records from multiple tables. This article will detail the differences between the two, allowing you to make the best choice for each unique scenario. You can use SQL’s UNION and UNION ALL commands to get data from multiple tables in your database. It’s a common use case, considering that most databases have many tables. Both UNION and UNION ALL are known as set operators. In SQL, set operators combine the results of two or more queries into a single result. You can read more about set operators in this article . When comparing UNION vs. UNION ALL , there is one major difference: UNION only returns unique UNION ALL returns all records, including duplicates. If you feel like you would benefit from a well-structured, comprehensive course that covers foundational SQL, consider this SQL...