diff --git a/src/services/mysql.service.ts b/src/services/mysql.service.ts
index 107a72e..e938ec2 100644
--- a/src/services/mysql.service.ts
+++ b/src/services/mysql.service.ts
@@ -2,6 +2,7 @@ import mysql, {type Connection, type ConnectionOptions} from 'mysql2';
 import {Logger} from "tslog";
 import type {IDbModel} from "@interfaces/database/IDbModel";
 import type {IDbUser} from "@interfaces/database/IDbUser";
+import type IDbCategory from "@interfaces/database/IDbCategory";
 
 
 const access: ConnectionOptions = {
@@ -88,27 +89,27 @@ const MySqlService = {
 		 * Insert a user into the database.
 		 *
 		 * @param {MysqlHandler} handler - The MySQL database handler.
-		 * @param {IDbUser} userData - The user data to insert.
+		 * @param {IDbUser} data - The user data to insert.
 		 * @returns {Promise<void>} A promise that resolves if the user was inserted successfully, or rejects with an error.
 		 * @throws {Error} If an error occurs while executing the query.
 		 */
-		insert(handler: MysqlHandler, userData: IDbUser) {
+		insert(handler: MysqlHandler, data: IDbUser) {
 			return new Promise((resolve, reject) => {
-				if (!userData.id) return reject('Id is undefined');
-				if (userData.id.length !== 36) return reject('Id invalid');
+				if (!data.id) return reject('Id is undefined');
+				if (data.id.length !== 36) return reject('Id invalid');
 
 				const _sql = "INSERT INTO `users`(`id`,`username`, `firstname`, `lastname`, `dob`, `email`, `is_mail_verified`, `is_admin`, `gdpr`, `hash`) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)"
 				const _values = [
-					userData.id,
-					userData.username,
-					userData.firstname,
-					userData.lastname,
-					userData.dob,
-					userData.email,
-					userData.is_mail_verified,
-					userData.is_admin,
-					userData.gdpr,
-					userData.hash
+					data.id,
+					data.username,
+					data.firstname,
+					data.lastname,
+					data.dob,
+					data.email,
+					data.is_mail_verified,
+					data.is_admin,
+					data.gdpr,
+					data.hash
 				]
 				try {
 					resolve(handler.execute(_sql, _values))
@@ -121,37 +122,37 @@ const MySqlService = {
 		/**
 		 * Updates user data in the database.
 		 * @param {MysqlHandler} handler - The MySQL handler object.
-		 * @param {IDbUser} userData - The user data to be updated.
+		 * @param {IDbUser} data - The user data to be updated.
 		 * @returns {Promise<unknown>} - A promise that resolves when the update is successful.
 		 * @throws {Error} - If an error occurs during the update process.
 		 */
-		update(handler: MysqlHandler, userData: IDbUser): Promise<unknown> {
+		update(handler: MysqlHandler, data: IDbUser): Promise<unknown> {
 			return new Promise((resolve, reject) => {
-				if (!userData.id) return reject('Id is undefined');
-				if (userData.id.length !== 36) return reject('Id invalid');
+				if (!data.id) return reject('Id is undefined');
+				if (data.id.length !== 36) return reject('Id invalid');
 
         try {
 					const _template = `
-						${userData.username 					? "`username` = ?," 				: null}
-						${userData.firstname 					? "`firstname` = ?," 				: null}
-						${userData.lastname 					? "`lastname` = ?," 				: null}
-						${userData.dob 								? "`dob` = ?," 							: null}
-						${userData.email 							? "`email` = ?," 						: null}
-						${userData.is_mail_verified 	? "`is_mail_verified` = ?,"	: null}
-						${userData.is_admin 					? "`is_admin` = ?," 				: null}
-						${userData.gdpr 							? "`gdpr` = ?," 						: null}
-						${userData.hash 							? "`hash` = ?" 							: null}`
+						${data.username 					? "`username` = ?," 				: null}
+						${data.firstname 					? "`firstname` = ?," 				: null}
+						${data.lastname 					? "`lastname` = ?," 				: null}
+						${data.dob 								? "`dob` = ?," 							: null}
+						${data.email 							? "`email` = ?," 						: null}
+						${data.is_mail_verified 	? "`is_mail_verified` = ?,"	: null}
+						${data.is_admin 					? "`is_admin` = ?," 				: null}
+						${data.gdpr 							? "`gdpr` = ?," 						: null}
+						${data.hash 							? "`hash` = ?" 							: null}`
 					const _values = [
-						userData.username,
-						userData.firstname,
-						userData.lastname,
-						userData.dob,
-						userData.email,
-						userData.is_mail_verified,
-						userData.is_admin,
-						userData.gdpr,
-						userData.hash,
-						userData.id
+						data.username,
+						data.firstname,
+						data.lastname,
+						data.dob,
+						data.email,
+						data.is_mail_verified,
+						data.is_admin,
+						data.gdpr,
+						data.hash,
+						data.id
 					]
 
 					const _sql = `UPDATE "users" SET ${_template} WHERE 'id' = ?`;