Do you use GROUP BY correctly?(dbasquare.com)

7 pointsby donteatbark14 ปีที่แล้ว1 comments

http://www.dbasquare.com/2012/05/15/mysql-mistakes-do-you-use-group-by-correctly/

1 comments

Jare14 ปีที่แล้ว

I often include such columns during ad-hoc analytics, because it is one valid example of the data being grouped. In particular, when COUNT(*) is 1 the value in that column is THE value, and thanks to including it in the query, I already have it. It's very convenient with very low cost.

For queries that are part of a formal process or application it's harder to find a use case.