[Rails5] Support 2014, 2012 drop table statement.

Author: metaskills

lib/active_record/connection_adapters/sqlserver/schema_statements.rb

@@ -42,6 +42,14 @@ def create_table(table_name, comment: nil, **options)
           res
         end
 
+        def drop_table(table_name, options = {})
+          if options[:if_exists] && @version_year != 2016
+            execute "IF EXISTS(SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = #{quote(table_name)}) DROP TABLE #{quote_table_name(table_name)}"
+          else
+            super
+          end
+        end
+
         def indexes(table_name, name = nil)
           data = select("EXEC sp_helpindex #{quote(table_name)}", name) rescue []
           data.reduce([]) do |indexes, index|

lib/active_record/connection_adapters/sqlserver_adapter.rb

@@ -339,6 +339,7 @@ def connect
                         dblib_connect(config)
                       end
         @spid = _raw_select('SELECT @@SPID', fetch: :rows).first.first
+        @version_year = version_year
         configure_connection
       end
 
@@ -415,6 +416,13 @@ def initialize_dateformatter
         }
       end
 
+      def version_year
+        vstring = _raw_select('SELECT @@version', fetch: :rows).first.first.to_s
+        /SQL Server (\d+)/.match(vstring).to_a.last.to_s.to_i
+      rescue Exception => e
+        2016
+      end
+
     end
   end
 end