Fix productivity analytics listing with multiple labels

changelogs/unreleased/33182-fix-productivity-analytics-multiple-labels-bug.yml

+---
+title: Fix productivity analytics listing with multiple labels
+merge_request: 33182
+author:
+type: fixed

ee/app/models/productivity_analytics.rb

@@ -43,28 +43,36 @@ class ProductivityAnalytics
     end
     columns.unshift(MergeRequest.arel_table[Arel.star])
 
-    mrs = merge_requests.select(columns)
-    mrs = mrs.reorder(custom_sorting) if custom_sorting
-    mrs
+    MergeRequest.joins(:metrics).select(columns).where(id: merge_requests).order(sorting)
   end
 
   private
 
   def histogram_query(column)
-    merge_requests.except(:select).select("#{column} as metric, count(*) as mr_count").group(column).reorder(nil)
+    MergeRequest::Metrics.joins(:merge_request)
+      .where(merge_request_id: merge_requests)
+      .select("#{column} as metric, count(*) as mr_count")
+      .group(column)
   end
 
   def scatterplot_query(column)
-    merge_requests.except(:select).select("#{column} as metric, merge_requests.id, merge_request_metrics.merged_at").reorder("merge_request_metrics.merged_at ASC")
+    merge_requests
+      .except(:select)
+      .select("#{column} as metric, merge_requests.id, merge_request_metrics.merged_at")
+      .reorder("merge_request_metrics.merged_at ASC")
   end
 
-  def custom_sorting
-    return unless sort
+  def sorting
+    return default_sorting unless sort
 
     column, direction = sort.split(/_(asc|desc)$/i)
 
-    return unless column.in?(METRIC_TYPES)
+    return default_sorting unless column.in?(METRIC_TYPES)
 
     Arel.sql("#{column} #{direction}")
   end
+
+  def default_sorting
+    {id: :desc}
+  end
 end