Databases SQL Reporting by Example Day 2: Advanced Selecting Day 2: Review

How can "GROUP BY" act on non-column values?

There are 267 employees and 15 with last names starting with 'A'. What does this return?

SELECT COUNT(1) FROM EMPLOYEES GROUP BY 'A';

1 Answer

Steven Parker
Steven Parker
177,670 Points

It doesn't exactly "act on" the constant value, that's part of the point of the question. The fact that the grouping is not being done on a value related to any column determines what will be returned in the result.

Great, thanks!