Added support for STRAIGHT_JOIN in ActiveRecord; #3073

[robinsowell]

Added straight as a join type

Not adding it as a flag/keyword, though first commit has both

NOTE - removed the flag from the final commit per discussion

per user request, adding a straight join flag and join type.

used as join('channel_data', "channel_data.entry_id = channel_titles.entry_id", "straight");

SELECT exp_channel_titles.entry_id FROM (exp_channel_titles) STRAIGHT_JOIN exp_channel_data ON exp_channel_data.entry_id

used as ->straight()

SELECT STRAIGHT_JOIN exp_channel_titles.entry_id FROM (exp_channel_titles

docs pr: ExpressionEngine/ExpressionEngine-User-Guide#678

[bryannielsen]

@robinsowell is this syntax for the second usage correct?

SELECT STRAIGHT_JOIN exp_channel_titles.entry_id FROM (exp_channel_titles

I don't have much experience with Straight Joins but in the little research I did it seems like it should be used in a similar way as other Joins. I can't find any references where it is part of the SELECT clause, maybe you can send me some links on that?

[robinsowell]

@bryannielsen Does this help? https://blog.sqlauthority.com/2014/03/12/mysql-how-to-do-straight-join-in-mysql/

I was puzzled by the two different approaches at first, but poked around and added it for someone who had a really big speed improvement using it in one particular circumstance- thing it was actually in a solspace add-on. But we needed it in native AR to apply it.

It did/does work for the end user, so even though obscure, I added it.

[bryannielsen]

@robinsowell was it just the SELECT STRAIGHT_JOIN that helped the customer? I just haven't seen that used much and I think we would rather encourage specifying the join type on the join() instead. I'm leaning towards removing the ->straight(bool) for selects and just keeping it as a new join type option unless there's a benefit to having the other. If we do want to keep it I think I would remove the boolean argument so you're either forcing a query to use straight joins or not, or is there a use case for where you would use ->straight(false) to turn off the straight join behavior on a query?

[intoeetive]

Robin to say final word, but I think straight_join is a modifier for select, not actually join type. And it needs to be treated sane way as 'distinct'

[bryannielsen]

@intoeetive I don't think that's actually the intended usage though. The docs only mention using it as a join type - https://dev.mysql.com/doc/refman/8.0/en/join.html but I think it's possible to use it through a select, just like you can technically join tables without a join statement. I just think if there's no benefit to this approach we shouldn't bother supporting it as it just causes more confusion

[robinsowell]

In truth, this was a pure FR from a user- I think they wanted to use it on a Solspace Calendar query that was being super slow for them (had to be something to do with the way mysql was doing the join), and having the flag was a billion times easier to implement. I'll see if I can find the support discussion.

[robinsowell]

Agreed- I think adding the straight_join as a join type makes sense. I'll drop the flag as it looks like it's non-recommended.

[TomJaeger]

My gut is that we fall in line with the existing join_type param on the method. and add it there.

https://docs.expressionengine.com/latest/development/legacy/database/active-record.html#jointable-cond-type--

[robinsowell]

@bryannielsen When you get a chance, can you take a look at this one again? I pulled out the flag/keyword, so it's just adding a straight join type. Tested doing

ee()->db->select('channel_name');
ee()->db->from('channels');
ee()->db->join('comments', 'comments.channel_id = channels.channel_id', STRAIGHT);
ee()->db->join('members', 'comments.author_id = members.member_id', STRAIGHT);
$query = ee()->db->get();