Fix regression on `.select_*` methods.

This was a common pattern:
```
query = author.posts.select(:title)
connection.select_one(query)
```

However `.select` returns a ActiveRecord::AssociationRelation, which has
the bind information, so we can use that to get the right sql query.

Also fix select_rows on postgress and sqlite3 that were not using the binds

[fixes #7538]
[fixes #12017]
[related #13731]
[related #12056]

1 files changed, 23 insertions, 0 deletions

diff --git a/activerecord/test/cases/adapter_test.rb b/activerecord/test/cases/adapter_test.rb
index b67e70ec7e..0eb1231c79 100644
--- a/activerecord/test/cases/adapter_test.rb
+++ b/activerecord/test/cases/adapter_test.rb
@@ -1,5 +1,7 @@
 require "cases/helper"
 require "models/book"
+require "models/post"
+require "models/author"
 
 module ActiveRecord
   class AdapterTest < ActiveRecord::TestCase
@@ -179,6 +181,27 @@ module ActiveRecord
       assert result.is_a?(ActiveRecord::Result)
     end
 
+    def test_select_methods_passing_a_association_relation
+      author = Author.create!(name: 'john')
+      Post.create!(author: author, title: 'foo', body: 'bar')
+      query = author.posts.select(:title)
+      assert_equal({"title" => "foo"}, @connection.select_one(query.arel, nil, query.bind_values))
+      assert_equal({"title" => "foo"}, @connection.select_one(query))
+      assert @connection.select_all(query).is_a?(ActiveRecord::Result)
+      assert_equal "foo", @connection.select_value(query)
+      assert_equal ["foo"], @connection.select_values(query)
+    end
+
+    def test_select_methods_passing_a_relation
+      Post.create!(title: 'foo', body: 'bar')
+      query = Post.where(title: 'foo').select(:title)
+      assert_equal({"title" => "foo"}, @connection.select_one(query.arel, nil, query.bind_values))
+      assert_equal({"title" => "foo"}, @connection.select_one(query))
+      assert @connection.select_all(query).is_a?(ActiveRecord::Result)
+      assert_equal "foo", @connection.select_value(query)
+      assert_equal ["foo"], @connection.select_values(query)
+    end
+
     test "type_to_sql returns a String for unmapped types" do
       assert_equal "special_db_type", @connection.type_to_sql(:special_db_type)
     end