Initial Import: Database transaction handling.

Initial Import: Error handling using ewf error library.
Added a CMS_ERROR_FILTER as part of registered filters of CMS_SERVICE

persistence/implementation/common/database/database_query.e

@@ -8,14 +8,14 @@ class
 
 inherit
 
-	SHARED_ERROR
+	SHARED_ERROR_HANDLER
 
 	REFACTORING_HELPER
 
 create
 	data_reader
 
-feature -- Intialization
+feature {NONE} -- Intialization
 
 	data_reader (a_query: STRING; a_parameters: STRING_TABLE [detachable ANY])
 			-- SQL data reader for the query `a_query' with arguments `a_parameters'
@@ -29,6 +29,8 @@ feature -- Intialization
 			parameters_set: parameters = a_parameters
 		end
 
+feature -- Execution		
+
 	execute_reader (a_base_selection: DB_SELECTION): detachable LIST [DB_RESULT]
 			-- Execute the Current sql query.
 		do
@@ -42,7 +44,6 @@ feature -- Intialization
 				a_base_selection.load_result
 				Result := a_base_selection.container
 			else
-				set_last_error (a_base_selection.error_message_32, generator + ".execute_reader"  )
 				log.write_error (generator + "." + a_base_selection.error_message_32)
 			end
 			unset_map_name (a_base_selection)
@@ -50,17 +51,12 @@ feature -- Intialization
 		end
 
 	execute_change (a_base_change: DB_CHANGE)
-			-- Execute the Current sql query .
+			-- Execute the Current sql query to change/update data in the database.
 		do
 			to_implement ("Check test dynamic sequel. to redesign.")
 			set_map_name (a_base_change)
 			a_base_change.set_query (query)
 			a_base_change.execute_query
-			if a_base_change.is_ok then
-			else
-				set_last_error (a_base_change.error_message_32, generator + ".execute_reader"  )
-				log.write_error (generator + "." + a_base_change.error_message_32)
-			end
 			unset_map_name (a_base_change)
 		end
 
@@ -72,17 +68,6 @@ feature --  Access
 	parameters: STRING_TABLE [detachable ANY]
 			-- query parameters.
 
-feature -- Status Report
-
-	has_error: BOOLEAN
-		-- is there an error?
-
-	error_message: detachable STRING_32
-		-- Error message if any.
-
-	error_code: INTEGER
-		-- Error code.
-
 feature {NONE} -- Implementation
 
 	set_map_name (a_base_selection: DB_EXPRESSION)
@@ -140,4 +125,4 @@ feature {NONE} -- Implementation
 		end
 
 
-end -- ESA_DATABASE_QUERY
+end -- DATABASE_QUERY