SQL UNION Operator Tutorial With Example | Union Clause in SQL is today’s topic. SQL UNION operator is used to combine a result sets of 2 or more  SELECT statements. It removes the duplicate rows between the several SELECT statements.

What is the use of Union Operator

A UNION operator is used to combine a result-set of two or more  SELECT statements.

1. Each SELECT statement within a UNION must have the same number of columns selected.
2. It should have the same number of columns expressions and same datatypes written with the same order.
3. The columns in each SELECT statement should also be in the same order.
4. The result set obtained by Union clause excluding the duplicate rows between the various results set.

In this article, we’ll review:

1. UNION and UNION all and how they work.
2. We discuss the rules for using UNION vs. UNION ALL.
3. SQL Operator Syntax.
4. How to use the simple SQL UNION clause in the select statement.
5. How to use the SQL UNION with the queries that have a  WHERE clause.

#sql #sql union