lib/generators/metka/strategies/materialized_view/templates/migration.rb.erb in metka-0.1.2 vs lib/generators/metka/strategies/materialized_view/templates/migration.rb.erb in metka-1.0.0

@@ -1,40 +1,47 @@
 # frozen_string_literal: true
 
 class <%= @migration_class_name %> < ActiveRecord::Migration<%= ActiveRecord::VERSION::MAJOR < 5 ? '' : '[5.0]' %>
   def up
     execute <<-SQL
-    CREATE 
-      OR REPLACE FUNCTION metka_refresh_<%= view_name %>_materialized_view RETURNS TRIGGER LANGUAGE plpgsql AS $$
+    CREATE OR REPLACE FUNCTION metka_refresh_<%= view_name %>_materialized_view() RETURNS trigger LANGUAGE plpgsql AS $$
       BEGIN
         IF TG_OP = 'INSERT' AND NEW.<%= source_column_name %> IS NOT NULL THEN
           REFRESH MATERIALIZED VIEW CONCURRENTLY <%= view_name %>;
-        ELSIF TG_OP = 'UPDATE' AND OLD.<%= source_column_name %> IS NOT NULL AND NEW.<%= source_column_name %> IS NOT NULL THEN
+        END IF;
+
+        IF TG_OP = 'UPDATE' AND OLD.<%= source_column_name %> != NEW.<%= source_column_name %> THEN
           REFRESH MATERIALIZED VIEW CONCURRENTLY <%= view_name %>;
-        ELSIF TG_OP = 'DELETE' AND OLD.<%= source_column_name %> IS NOT NULL THEN
+        END IF;
+
+        IF TG_OP = 'DELETE' AND OLD.<%= source_column_name %> IS NOT NULL THEN
           REFRESH MATERIALIZED VIEW CONCURRENTLY <%= view_name %>;
         END IF;
+        RETURN NEW;
+      END $$;
 
-      RETURN NULL;
-    END $$;
+    DROP MATERIALIZED VIEW IF EXISTS <%= view_name %>;
+    CREATE MATERIALIZED VIEW <%= view_name %> AS
+      SELECT UNNEST
+        ( <%= source_column_name %> ) AS <%= source_column_name.singularize %>_name,
+        COUNT ( * ) AS taggings_count
+      FROM
+        <%= source_table_name %>
+      GROUP BY
+        <%= source_column_name.singularize %>_name;
 
-    CREATE OR REPLACE MATERIALZIED VIEW <%= view_name %> AS
+    CREATE UNIQUE INDEX idx_<%= source_table_name %>_<%= source_column_name %> ON <%= view_name %>(<%= source_column_name.singularize %>_name);
 
-    SELECT UNNEST
-      ( <%= source_column_name %> ) AS <%= source_column_name.singularize %>_name,
-      COUNT ( * ) AS taggings_count
-    FROM
-      <%= source_table_name %>
-    GROUP BY
-      <%= source_column_name.singularize %>_name;
-
     CREATE TRIGGER metka_on_<%= source_table_name %>
-    BEFORE UPDATE OR INSERT OR DELETE ON <%= source_table_name %> FOR EACH ROW
-    EXECUTE PROCEDURE metka_refresh_<%= view_name %>_materialized_view();    
+    AFTER UPDATE OR INSERT OR DELETE ON <%= source_table_name %> FOR EACH ROW
+    EXECUTE PROCEDURE metka_refresh_<%= view_name %>_materialized_view();
+    SQL
   end
 
   def down
     execute <<-SQL
-      DROP VIEW <%= view_name %>;
+      DROP TRIGGER IF EXISTS metka_on_<%= source_table_name %> ON <%= source_table_name %>;
+      DROP FUNCTION IF EXISTS metka_refresh_<%= view_name %>_materialized_view;
+      DROP MATERIALIZED VIEW IF EXISTS <%= view_name %>;
     SQL
   end
 end