feat(services): update MySQL service to fetch brand data

- Corrected the SQL query in fetching brand data based on ID.
- Added a new function, `getBySlug`, to fetch brand data using the brand slug. This ensures a flexible data access method thus enhancing the service's usability.

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

src/controllers/category.controller.ts

@@ -118,7 +118,15 @@ async function getAllCategory(res: Response): Promise<Response> {
 	});
 }
 
-async function getBySlugCategory(req: Request, res:Response) {
+/**
+ * Get category by slug
+ *
+ * @param {Request} req - The request object containing category slug
+ * @param {Response} res - The response object to send back the category
+ *
+ * @return {Promise<Response>} - The response with category data or error message
+ */
+async function getBySlugCategory(req: Request, res:Response): Promise<Response> {
 	const categorySlug = req.params["categorySlug"];
     if (!categorySlug) {
       logger.error("Category slug is missing");

src/services/mysql.service.ts

@@ -348,6 +348,50 @@ const MySqlService = {
 					reject(err as Error);
 				}
 			})
+		},
+
+		/**
+		 * Fetches a category by its Id
+		 *
+		 * @param {MysqlHandler} handler - The instance of the MysqlHandler used for executing the query
+		 * @param {string} brandId - The Id of the category to be fetched
+		 * @return {Promise<IDbBrand>} - A promise that, when resolved, returns the category matching the Id
+		 * @throws {Error} - If an error occurs during execution
+		 * @throws {string} - If brandId is undefined or invalid
+		 */
+		getById(handler: MysqlHandler, brandId: string): Promise<IDbBrand> {
+			return new Promise((resolve, reject) => {
+				if (!brandId) return reject('slug is undefined')
+				if (brandId.length !== 36) return reject('Id invalid');
+				const _sql = "SELECT * FROM `brands` WHERE `id` = ?";
+				const _values = [brandId];
+				try {
+					resolve(handler.execute(_sql, _values) as unknown as IDbBrand);
+				} catch (err: unknown) {
+					//TODO Reject with null and logger error
+					reject(err as Error);
+				}
+			})
+		},
+
+		/**
+		 * Retrieves a brand from the database by its slug.
+		 *
+		 * @param {MysqlHandler} handler - The MySQL handler object used to connect to the database.
+		 * @param {string} brandSlug - The slug of the brand to retrieve.
+		 * @returns {Promise<IDbBrand>} - A promise that resolves with the brand object if found, or rejects with an error message.
+		 */
+		getBySlug(handler: MysqlHandler, brandSlug: string): Promise<IDbBrand> {
+			return new Promise((resolve, reject) => {
+				if (!brandSlug) return reject('slug is undefined')
+				const _sql = "SELECT * FROM `brands` WHERE `slug_name` = ?";
+				const _values = [brandSlug];
+				try {
+					resolve(handler.execute(_sql, _values) as unknown as IDbBrand);
+				} catch (err: unknown) {
+					reject(err as Error);
+				}
+			})
 		}
 	},
 	Model: {