What is the SQL UNION operator and how do I use it?

What is the SQL UNION operator and how do I use it?

The SQL UNION operator is used to combine the results of two or more SELECT statements. It removes duplicate rows between the result sets.

Can you give me an example of how to use it?

Sure! Here's a simple example: SELECT column1 FROM table1 UNION SELECT column1 FROM table2; This combines results from both tables.

What if the columns have different names?

If the columns have different names, you can use aliases. For example: SELECT column1 AS name FROM table1 UNION SELECT column2 AS name FROM table2;

Are there any limitations to using UNION?

Yes, all SELECT statements must have the same number of columns, and the corresponding columns must have compatible data types.