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author | Yorick Peterse <yorickpeterse@gmail.com> | 2018-09-11 18:31:34 +0300 |
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committer | Yorick Peterse <yorickpeterse@gmail.com> | 2018-09-17 13:39:43 +0300 |
commit | 8a72f5c427426a3f90a14b2711ee1ecec4e8ca40 (patch) | |
tree | e8fad1dd2d9036b50cf42c46518da95e186679fd /app/finders/union_finder.rb | |
parent | 78b3eea7d248c6d3c48b615c9df24a95cb5fd1d8 (diff) |
Added FromUnion to easily select from a UNION
This commit adds the module `FromUnion`, which provides the class method
`from_union`. This simplifies the process of selecting data from the
result of a UNION, and reduces the likelihood of making mistakes. As a
result, instead of this:
union = Gitlab::SQL::Union.new([foo, bar])
Foo.from("(#{union.to_sql}) #{Foo.table_name}")
We can now write this instead:
Foo.from_union([foo, bar])
This commit also includes some changes to make this new setup work
properly. For example, a bug in Rails 4
(https://github.com/rails/rails/issues/24193) would break the use of
`from("sub-query-here").includes(:relation)` in certain cases. There was
also a CI query which appeared to repeat a lot of conditions from an
outer query on an inner query, which isn't necessary.
Finally, we include a RuboCop cop to ensure developers use this new
module, instead of using Gitlab::SQL::Union directly.
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/51307
Diffstat (limited to 'app/finders/union_finder.rb')
-rw-r--r-- | app/finders/union_finder.rb | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/app/finders/union_finder.rb b/app/finders/union_finder.rb index 798c3eba0f3..c3b02f7e52f 100644 --- a/app/finders/union_finder.rb +++ b/app/finders/union_finder.rb @@ -1,15 +1,15 @@ # frozen_string_literal: true class UnionFinder - # rubocop: disable CodeReuse/ActiveRecord def find_union(segments, klass) - if segments.length > 1 - union = Gitlab::SQL::Union.new(segments.map { |s| s.select(:id) }) + unless klass < FromUnion + raise TypeError, "#{klass.inspect} must include the FromUnion module" + end - klass.where("#{klass.table_name}.id IN (#{union.to_sql})") + if segments.length > 1 + klass.from_union(segments) else segments.first end end - # rubocop: enable CodeReuse/ActiveRecord end |