SQL EXCEPT Operator - Complete Beginner Tutorial

What is the SQL EXCEPT Operator?

The EXCEPT operator returns all distinct rows from the first query that are not found in the second query. It effectively subtracts the second dataset from the first.

It is part of SQL's set operators, alongside UNION and INTERSECT, which combine or compare query results.

• Returns distinct rows from the first query only.
• Removes duplicates automatically.
• Requires both queries to have the same number of columns.
• Columns must have compatible data types.

Syntax and Usage

The basic syntax for EXCEPT is straightforward. You write two SELECT statements separated by the EXCEPT keyword.

Both SELECT statements must select the same number of columns with compatible data types.

• SELECT column_list FROM table1
• EXCEPT
• SELECT column_list FROM table2;

Example of SQL EXCEPT

Consider two tables, Employees2023 and Employees2024. To find employees who were in 2023 but not in 2024, you can use EXCEPT.