This SQL tutorial explains how to use the SQL MINUS operator with syntax and examples.
The SQL MINUS operator is used to return all rows in the first SELECT statement that are not returned by the second SELECT statement. Each SELECT statement will define a dataset. The MINUS operator will retrieve all records from the first dataset and then remove from the results all records from the second dataset.
Explanation: The MINUS query will return the records in the blue shaded area. These are the records that exist in Dataset1 and not in Dataset2.
Each SELECT statement within the MINUS query must have the same number of fields in the result sets with similar data types.
The MINUS operator is not supported in all SQL databases. It can used in databases such as Oracle.
For databases such as SQL Server, PostgreSQL, and SQLite, use the EXCEPT operator to perform this type of query.
The syntax for the SQL MINUS operator is:
SELECT expression1, expression2, ... expression_n FROM tables WHERE conditions MINUS SELECT expression1, expression2, ... expression_n FROM tables WHERE conditions;
The following is a SQL MINUS operator example that has one field with the same data type:
SELECT supplier_id FROM suppliers MINUS SELECT supplier_id FROM orders;
This SQL MINUS example returns all supplier_id values that are in the suppliers table and not in the orders table. What this means is that if a supplier_id value existed in the suppliers table and also existed in the orders table, the supplier_id value would not appear in this result set.
The following is a MINUS operator example that uses the ORDER BY clause:
SELECT supplier_id, supplier_name FROM suppliers WHERE supplier_id > 2000 MINUS SELECT company_id, company_name FROM companies WHERE company_id > 1000 ORDER BY 2;
In this SQL MINUS operator example, since the column names are different between the two SELECT statements, it is more advantageous to reference the columns in the ORDER BY clause by their position in the result set. In this example, we've sorted the results by supplier_name / company_name in ascending order, as denoted by the
ORDER BY 2.
The supplier_name / company_name fields are in position #2 in the result set.