Added Redshift hack for Groupdate

app/controllers/blazer/queries_controller.rb

@@ -41,6 +41,8 @@ module Blazer
           @sql_errors << error if error
         end
       end
+
+      data_source.groupdate_hack(@statement)
     end
 
     def edit
@@ -56,6 +58,8 @@ module Blazer
 
         data_source = params[:data_source]
         data_source = @query.data_source if @query && @query.data_source
+        @data_source = Blazer.data_sources[data_source]
+        @data_source.groupdate_hack(@statement)
 
         # audit
         if Blazer.audit
@@ -66,7 +70,6 @@ module Blazer
           audit.save!
         end
 
-        @data_source = Blazer.data_sources[data_source]
         @rows, @error, @cached_at = @data_source.run_statement(@statement, user: blazer_user, query: @query, refresh_cache: params[:check])
 
         if @query && !@error.to_s.include?("canceling statement due to statement timeout")

lib/blazer/data_source.rb

@@ -71,7 +71,7 @@ module Blazer
 
         in_transaction do
           begin
-            connection_model.connection.execute("SET statement_timeout = #{timeout.to_i * 1000}") if timeout && postgresql?
+            connection_model.connection.execute("SET statement_timeout = #{timeout.to_i * 1000}") if timeout && (postgresql? || redshift?)
             result = connection_model.connection.select_all("#{statement} /*#{comment}*/")
             result.each do |untyped_row|
               row = {}
@@ -100,7 +100,7 @@ module Blazer
     end
 
     def schemas
-      default_schema = postgresql? ? "public" : connection_model.connection_config[:database]
+      default_schema = (postgresql? || redshift?) ? "public" : connection_model.connection_config[:database]
       settings["schemas"] || [connection_model.connection_config[:schema] || default_schema]
     end
 
@@ -110,7 +110,25 @@ module Blazer
     end
 
     def postgresql?
-      ["PostgreSQL", "Redshift"].include?(connection_model.connection.adapter_name)
+      connection_model.connection.adapter_name == "PostgreSQL"
+    end
+
+    def redshift?
+      connection_model.connection.adapter_name == "Redshift"
+    end
+
+    def groupdate_hack(statement)
+      if redshift? && Blazer.settings["groupdate_hack"]
+        original_statement = statement.dup
+        %w[day week month].each do |period|
+          statement.gsub!(/g#{period}\(([^,\)]+), ?([^\)]+)\)/, "TRUNC(DATE_TRUNC('#{period}', CONVERT_TIMEZONE(\\2, \\1)))")
+          statement.gsub!(/g#{period}\(([^\)]*_at[^\)]*)\)/, "TRUNC(DATE_TRUNC('#{period}', CONVERT_TIMEZONE('America/Los_Angeles', \\1)))")
+          statement.gsub!(/g#{period}\(([^\)]+)\)/, "TRUNC(DATE_TRUNC('#{period}', \\1))")
+        end
+        if statement != original_statement
+          statement << "\n/* modified for Redshift */"
+        end
+      end
     end
 
     protected