In MySQL
I use a lot constructs which look like this:
LEFT JOIN(
SELECT field_one, field_two, field_three FROM (
SELECT field_one, field_two, field_three FROM table_one
ORDER BY field_three
) o GROUP BY field_one
) abc ON cur_table.some_field = abc.field_one
I use it, because it helps me to implement a usual task - to order some data before grouping. Now I wonder if it is possible to migrate this sql construct from MySQL
to SQLite
and Postgresql
.
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