How to Order Results Before Grouping in MySQL?

MySQL Order before Group By

In MySQL, executing a GROUP BY clause normally orders the results after the groups have been formed. However, there are scenarios where you want to order the results before grouping.

Consider the following query:

This query aims to find the latest post for each author and then group the results. However, the problem is that it sorts the results after grouping, not before.

Solution

To order the results before grouping, you can use the following approach:

The HAVING clause ensures that only the latest post for each author is selected before grouping.

Alternative Solution

In cases where the HAVING clause is not feasible, such as in Postgres or SQL Server, you can use the following alternative solution:

This query uses a subquery to find the maximum post date for each author and then joins it with the original table to retrieve the actual post records.

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