使用“具有”的ActiveRecord关系的rails update_all不起作用

Question

Sample:

a = Model.join("...").where("...").group("...")
b = Model.join("...").where("...").group("...").having("...")

If I do:

a.class gives me ActiveRecord::Relation. Same with b.class .

When I do:

a.length i get 1000 . And b.length i get 50

And finally, if i do:

a.update_all(field:'...')
=> 1000

b.update_all(field:'...')
=> 1000

Not 50 , as I was expecting.

Why this happen? Is there any way to deal with this?

Answer 1

update_all only takes the constraints from your query and ignores the group and having clauses.

Here is the source code of update_all

def update_all(updates)
    .....
    # HERE IS THE RELEVANT CODE
    # It extracts only the constraints, limit and order clauses. It ignores the rest
    stmt.take(arel.limit)
    stmt.order(*arel.orders)
    stmt.wheres = arel.constraints
    .....
end

I guess you would have to do it in two steps, execute your query with the having clause and get the list IDs for the 50 records that match and then do an update_all on these records using an IN clause