How Can I Achieve a MINUS Operation in MySQL?

Trying to Perform Minus Operation in MySQL

Many users encounter the challenge of performing MINUS operations in MySQL. Unlike Oracle, MySQL does not natively support these operations. However, there are alternative approaches available to achieve similar results.

To illustrate, consider three tables with the following schemas:

• Service_Details: Contains details about services, including their Service_Code, Service, and Name.
• Servicing_States: Maintains information about states where services are offered. It includes columns for Service_Code, State, and Country.
• Exception Table: Lists exceptions, such as ZIP codes and states where services are not provided. It contains columns for Service_Code, Zipcode, and State.

To retrieve the desired output, which displays the difference between two SELECT queries, MySQL users can utilize the NOT IN operator. This operator acts as a substitute for the MINUS operation, allowing you to exclude records from one query that are present in another.

For instance, the following query can be used to obtain the output:

SELECT a.id 
FROM table1 AS a 
WHERE <condition> 
AND a.id NOT IN (SELECT b.id 
                  FROM table2 AS b 
                  WHERE <condition>);

This query effectively removes the records from the second query (table2) that are also present in the first query (table1), providing the desired result.

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