Fix tests for prepared_statements: false and queries hitting `#select_all`

- The query needs to be executed for hitting `select_all` so made sure
  that query gets executed.
- Also instead of changing instance variable, just add new
  configuration for prepared_statements: false and use it for this
  test.
- This way we don't have to touch the internals of AR code and still
  disable prepared statements config for this test.

1 files changed, 2 insertions, 1 deletions

diff --git a/activerecord/test/support/config.rb b/activerecord/test/support/config.rb
index 5817e427e3..e1aa8d72e3 100644
--- a/activerecord/test/support/config.rb
+++ b/activerecord/test/support/config.rb
@@ -26,7 +26,8 @@ module ARTest
 
     def expand_config(config)
       config["connections"].each do |adapter, connection|
-        dbs = [["arunit", "activerecord_unittest"], ["arunit2", "activerecord_unittest2"]]
+        dbs = [["arunit", "activerecord_unittest"], ["arunit2", "activerecord_unittest2"],
+               ["arunit_with_prepared_statements", "activerecord_unittest"]]
         dbs.each do |name, dbname|
           unless connection[name].is_a?(Hash)
             connection[name] = { "database" => connection[name] }