Tags / union
Unpivoting and Repivoting in MySQL: A Case Study on Union Queries
Understanding SQL Server Performance Issues with EXCEPT Operator
How SQL Handles NULL Values When Using Union Queries to Preserve Nulls and Include All Relevant Data
Using UNION with Common Table Expressions in SQL Server 2014 Developer: Workarounds and Best Practices
Forcing Parallel Execution Plans in SQL Server: Alternative Solutions
5 Ways to Order Tables Differently with Union Clauses in SQL