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Asked: 2026-05-25T19:37:58+00:00

Sorry for the simple question, but I didn’t know the proper way to word

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Sorry for the simple question, but I didn’t know the proper way to word it to get useful results. I was wondering if there was a function in MySQL that supports a “has all” relationship. The term that I think I’m referring to is set division (when I look up division in the manual pages, I only see precision mathematical division in MySQL). So, for example, if I had a relation of students and courses, I might want to retrieve a list of courses in which ALL of the students are taking (perhaps, the course ID number appears under each student, or something similar). Does my question make sense? I can come up with a different query to get the job done, but it would be really nice if I could simplify it all with a simple built in function, you know?

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  1. Editorial Team

    No there isn’t. See Divided We Stand: The SQL of Relational Division for a good round up of approaches. The article is SQL Server centric but the same 2 approaches of GROUP BY ... HAVING COUNT or double NOT EXISTS still work.

    For exact relational division (with no remainder) GROUP_CONCAT could come in handy though.

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