Further remove code branches by database type

We dropped MySQL support and a lot of mysql specific code has been
removed in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/29608.

This comes in from the other direction and removes any `if postgresql?`
branches.

3 files changed, 4 insertions, 18 deletions

diff --git a/app/services/cohorts_service.rb b/app/services/cohorts_service.rb
index 6d466c2fc9c..97fbb70f350 100644
--- a/app/services/cohorts_service.rb
+++ b/app/services/cohorts_service.rb
@@ -95,10 +95,6 @@ class CohortsService
   # rubocop: enable CodeReuse/ActiveRecord
 
   def column_to_date(column)
-    if Gitlab::Database.postgresql?
-      "CAST(DATE_TRUNC('month', #{column}) AS date)"
-    else
-      "STR_TO_DATE(DATE_FORMAT(#{column}, '%Y-%m-01'), '%Y-%m-%d')"
-    end
+    "CAST(DATE_TRUNC('month', #{column}) AS date)"
   end
 end
diff --git a/app/services/projects/base_move_relations_service.rb b/app/services/projects/base_move_relations_service.rb
index 24dec1f3a45..b177837214d 100644
--- a/app/services/projects/base_move_relations_service.rb
+++ b/app/services/projects/base_move_relations_service.rb
@@ -13,14 +13,9 @@ module Projects
 
     private
 
-    # rubocop: disable CodeReuse/ActiveRecord
     def prepare_relation(relation, id_param = :id)
-      if Gitlab::Database.postgresql?
-        relation
-      else
-        relation.model.where("#{id_param}": relation.pluck(id_param))
-      end
+      # TODO: Refactor and remove this method (https://gitlab.com/gitlab-org/gitlab-ce/issues/65054)
+      relation
     end
-    # rubocop: enable CodeReuse/ActiveRecord
   end
 end
diff --git a/app/services/projects/fetch_statistics_increment_service.rb b/app/services/projects/fetch_statistics_increment_service.rb
index 8644e6bf313..b150fd2d9f1 100644
--- a/app/services/projects/fetch_statistics_increment_service.rb
+++ b/app/services/projects/fetch_statistics_increment_service.rb
@@ -12,14 +12,9 @@ module Projects
       increment_fetch_count_sql = <<~SQL
         INSERT INTO #{table_name} (project_id, date, fetch_count)
         VALUES (#{project.id}, '#{Date.today}', 1)
+        ON CONFLICT (project_id, date) DO UPDATE SET fetch_count = #{table_name}.fetch_count + 1
       SQL
 
-      increment_fetch_count_sql += if Gitlab::Database.postgresql?
-                                     "ON CONFLICT (project_id, date) DO UPDATE SET fetch_count = #{table_name}.fetch_count + 1"
-                                   else
-                                     "ON DUPLICATE KEY UPDATE fetch_count = #{table_name}.fetch_count + 1"
-                                   end
-
       ActiveRecord::Base.connection.execute(increment_fetch_count_sql)
     end