Learn what a SQL union is, how it works, and how you can use it to combine data from different tables or sources. Find examples and best practices for using a SQL union.

Arguments <query_specification> | ( <query_expression> ) Is a query specification or query expression that returns data to be combined with the data from another query specification or query ...

By default, the `UNION` operator in SQL is used to combine the result sets of two or more queries into a single result set. The main feature of the `UNION` operator is that it removes duplicates from ...

The UNION could be slower if you have a really big result set. It shouldn't, but I've run into it in the real world on SQL Server 2000.

This paper proposes a method SQL detection and algorithm to detect and prevent the tautology and union query based attacks at run time.

I need to form the equivalent of a Union Join in Oracle 8i, even though a Union Join doesn't appear to be supported in 8i. I might be able to manipulate a Full Outer Join to get the results I need ...

Joey on SQL Server A Deep Dive into SQL Server 2022's Query Performance Features, Part 1 An update to the cardinality estimator feature in SQL Server 2022 will be one of the biggest changes to the ...