Support for Multiple BY patterns in SORT Command

[idaunis]

With this feature Redis will expand the applications in numerous scenarios where right now can only be performed in an SQL-like environment.

Usage
SORT key [BY pattern [ASC|DESC] [ALPHA] [BY pattern…]] [LIMIT offset count] [GET pattern [GET pattern ...]] [STORE destination]

Documentation
The BY option can be used multiple times in order to sort by multiple fields. If the list elements have the same value when ordering by the first BY pattern, then it sorts by the second BY pattern and so on.

The following example will order the list mylist by weight and by title. Sorting first the list of elements by weight, and then by title when the elements have the same weight:

SORT mylist BY weight_* BY title_* ALPHA

[BharathZoho]

This seems to be very useful, When will this feature be added to the main branch?

[Jevin23]

+1

[fcerbell]

It would help me a lot, too.

[gkorland]

@idaunis can you please describe your use case?

[cscan]

This is my test case:

127.0.0.1:6380> hmset test:01 f1 345 f2 A
127.0.0.1:6380> hmset test:02 f1 444 f2 B
127.0.0.1:6380> hmset test:03 f1 776 f2 B
127.0.0.1:6380> hmset test:04 f1 111 f2 B
127.0.0.1:6380> hmset test:05 f1 999 f2 A
127.0.0.1:6380> sadd testset test:01
127.0.0.1:6380> sadd testset test:02
127.0.0.1:6380> sadd testset test:03
127.0.0.1:6380> sadd testset test:04
127.0.0.1:6380> sadd testset test:05
127.0.0.1:6380> sort testset by *->f2 alpha by *->f1
1) "test:04"
2) "test:01"
3) "test:02"
4) "test:03"
5) "test:05"

BTW, the result should be:

1) "test:01"
2) "test:05"
3) "test:04"
4) "test:02"
5) "test:03"

+11