feat(services): add update method to mysql service

An `update` method is added to the `mysql.service.ts` for handling database updates. This new function checks for validity of the `id` before constructing and executing an SQL update statement. Errors are also caught and handled.

Issue: #5
Signed-off-by: Mathis <yidhra@tuta.io>

src/services/mysql.service.ts

@@ -289,6 +289,31 @@ const MySqlService = {
 					reject(err as Error);
 				}
 			})
+		},
+		update(handler: MysqlHandler, data: IDbBrand) {
+			return new Promise((resolve, reject) => {
+				if (!data.id) return reject('Id is undefined');
+				if (data.id.length !== 36) return reject('Id invalid');
+
+				try {
+					const _template = `
+						${data.slug_name 			? "`slug_name` = ?," 				: null}
+						${data.display_name 	? "`display_name` = ?,"			: null}
+						${data.image_blob 		? "`slug_name` = ?," 				: null}`
+
+					const _values = [
+						data.slug_name,
+						data.display_name,
+						data.image_blob,
+						data.id
+					]
+					const _sql = `UPDATE "brands" SET ${_template} WHERE 'id' = ?`;
+					return resolve(handler.execute(_sql, _values));
+
+				} catch (err: unknown) {
+					reject(err as Error);
+				}
+			})
 		}
 
 	},