add delete option and error handling to tours

lib/db.vala

@@ -39,7 +39,11 @@ namespace LibSernatur {
 			/**
 			 * Invalid value
 			 */
-			INVALID_VALUE
+			INVALID_VALUE,
+			/**
+			 * Could not be modified or deleted because of a constraint
+			 */
+			FOREIGN_KEY_CONSTAINT
 		}
 
 		/**

lib/db/tour.vala

@@ -129,6 +129,29 @@ namespace LibSernatur {
 					#endif
 				}
 			}
+
+			/**
+			 * Delete a tour in the database
+			 * @param conn The database connection
+			 * @param tour The tour to update
+			 * @throws DBError Thrown if the data in the object is invalid
+			 */
+			public static void delete_tour (Database conn, Tour tour) throws DBError {
+				if (tour.id_tour == 0) {
+					throw new DBError.INVALID_VALUE (dgettext (null, "The id of the tour is invalid!"));
+				}
+				var res = conn.exec (Query.get_query (Query.Type.DELETE_TOUR, tour));
+				if (res.get_status () != ExecStatus.COMMAND_OK) {
+					if (res.get_error_field (FieldCode.SQLSTATE) == "23503") {
+						throw new DBError.FOREIGN_KEY_CONSTAINT (res.get_error_field (FieldCode.MESSAGE_PRIMARY));
+					}
+					#if DEBUG
+						error (conn.get_error_message ());
+					#else
+						warning (conn.get_error_message ());
+					#endif
+				}
+			}
 		}
 	}
 }

lib/queries.vala

@@ -21,30 +21,37 @@ namespace LibSernatur {
 			public enum Type {
 				SELECT_ALL_TOURS,
 				INSERT_TOUR,
-				UPDATE_TOUR
+				UPDATE_TOUR,
+				DELETE_TOUR
 			}
 
 			public static string get_query (Type type, T? t) {
-				if (type == Type.SELECT_ALL_TOURS) {
-					return "
+				switch (type) {
+					case SELECT_ALL_TOURS:
+						return "
 SELECT T.id_tour, T.nombre_tour, T.costo_indiv, T.costo_grupal, T.minima_personas,
 C.id_ciudad, C.nombre_ciudad,
 R.id_region, R.nombre_region
 FROM tour T
 JOIN ciudad C ON (T.id_ciudad = C.id_ciudad)
 JOIN region R ON (C.id_region = R.id_region)";
-				}
-				else if (type == Type.UPDATE_TOUR) {
-					Tour tour = (Tour) t;
-					return "
+					case UPDATE_TOUR:
+						Tour tour = (Tour) t;
+						return "
 UPDATE tour SET
 	nombre_tour = '" + tour.nombre_tour + "',
 	costo_indiv = " + tour.costo_indiv.to_string () + ",
 	costo_grupal = " + tour.costo_grupal.to_string () + ",
 	minima_personas = " + tour.minima_personas.to_string () + "
 WHERE id_tour = " + tour.id_tour.to_string ();
+					case DELETE_TOUR:
+						Tour tour = (Tour) t;
+						return "
+DELETE FROM tour
+WHERE id_tour = " + tour.id_tour.to_string ();
+					default:
+						return "";
 				}
-				return "";
 			}
 		}
 	}