better handling of updates with identiy column. Room for improvement.

Author: Anna Carey

lib/active_record/connection_adapters/sqlserver/database_statements.rb

@@ -14,20 +14,12 @@ def execute(sql, name = nil)
           end
         end
 
-        # TODO: I bet there's a better way than a regex to take care of this
         def exec_query(sql, name = 'SQL', binds = [], sqlserver_options = {})
-          # We can't update Identiy columns in sqlserver.  So, strip out the id from the update.
-          if sql =~ /UPDATE/
-            # take off a comma before or after.  This could probably be done better
-            if sql =~ /, \[id\] = @?[0-9]*/
-              sql.gsub!(/, \[id\] = @?[0-9]*/, '')
-            elsif sql =~ /\s\[id\] = @?[0-9]*,/
-              sql.gsub!(/\s\[id\] = @?[0-9]*,/, '')
-            end
-          end
-
           if id_insert_table_name = sqlserver_options[:insert] ? query_requires_identity_insert?(sql) : nil
             with_identity_insert_enabled(id_insert_table_name) { do_exec_query(sql, name, binds) }
+          elsif update_sql?(sql)
+             sql = strip_ident_from_update(sql)
+             do_exec_query(sql, name, binds)
           else
             do_exec_query(sql, name, binds)
           end

lib/active_record/connection_adapters/sqlserver/schema_statements.rb

@@ -366,6 +366,27 @@ def insert_sql?(sql)
           !(sql =~ /^\s*(INSERT|EXEC sp_executesql N'INSERT)/i).nil?
         end
 
+        def strip_ident_from_update(sql)
+          # We can't update Identiy columns in sqlserver.  So, strip out the id from the update.
+          # There has to be a better way to handle this, but this'll do for now.
+          table_name = get_table_name(sql)
+          id_column = identity_column(table_name)
+
+          if id_column
+            regex_col_name = Regexp.quote(quote_column_name(id_column.name))
+            if sql =~ /, #{regex_col_name} = @?[0-9]*/
+              sql = sql.gsub(/, #{regex_col_name} = @?[0-9]*/, '')
+            elsif sql =~ /\s#{regex_col_name} = @?[0-9]*,/
+              sql = sql.gsub(/\s#{regex_col_name} = @?[0-9]*,/, '')
+            end
+          end
+          sql
+        end
+
+        def update_sql?(sql)
+          !(sql =~ /^\s*(UPDATE|EXEC sp_executesql N'UPDATE)/i).nil?
+        end
+
         def with_identity_insert_enabled(table_name)
           table_name = quote_table_name(table_name_or_views_table_name(table_name))
           set_identity_insert(table_name, true)