diff --git a/documents/postman-collection/KasirAja API.postman_collection.json b/documents/postman-collection/KasirAja API.postman_collection.json
index 799bdd3..4d60be9 100644
--- a/documents/postman-collection/KasirAja API.postman_collection.json	
+++ b/documents/postman-collection/KasirAja API.postman_collection.json	
@@ -1292,7 +1292,7 @@
 						"method": "GET",
 						"header": [],
 						"url": {
-							"raw": "{{host}}/products?page=1&q=e&withStock=true",
+							"raw": "{{host}}/products?page=1&q=e&withStock=true&withCategory=true",
 							"host": [
 								"{{host}}"
 							],
@@ -1311,6 +1311,10 @@
 								{
 									"key": "withStock",
 									"value": "true"
+								},
+								{
+									"key": "withCategory",
+									"value": "true"
 								}
 							]
 						}
diff --git a/src/services/postgres/ProductsService.js b/src/services/postgres/ProductsService.js
index 1a6ce6f..5257e0b 100644
--- a/src/services/postgres/ProductsService.js
+++ b/src/services/postgres/ProductsService.js
@@ -10,7 +10,7 @@ class ProductsService {
   }
 
   async getProducts(companyId, {
-    page = 1, q = null, withStock, limit = 10,
+    page = 1, q = null, withStock = false, withCategory = false, limit = 10,
   }) {
     const recordsQuery = await this._pool.query(`
       SELECT count(id) as total 
@@ -25,30 +25,21 @@ class ProductsService {
     const totalPages = Math.ceil(total / limit);
     const offsets = limit * (page - 1);
 
-    let query = {
+    const query = {
       text: `SELECT 
-              id, name, description, price, cost
+              products.id, name, description, price, cost
+              ${withStock === 'true' ? ', stock' : ''}
+              ${withCategory === 'true' ? ', categories.name as category_name' : ''}
             FROM products
-            WHERE company_id = $1 
-            ${q !== null ? `AND name ILIKE '%${q}%'` : ''}
+            ${withStock === 'true' ? 'LEFT JOIN stocks ON stocks.product_id = products.id' : ''}
+            ${withCategory === 'true' ? 'LEFT JOIN categories ON categories.id = products.category_id' : ''}
+            WHERE company_id = $1
+            ${q ? `AND name ILIKE '%${q}%'` : ''}
+            ORDER BY products.created_at DESC
             LIMIT $2 OFFSET $3`,
       values: [companyId, limit, offsets],
     };
 
-    if (withStock && withStock === 'true') {
-      query = {
-        text: `SELECT 
-                name, description, price, cost, stock
-              FROM products
-              LEFT JOIN stocks ON stocks.product_id = products.id
-              WHERE company_id = $1 
-              ${q !== null ? `AND name ILIKE '%${q}%'` : ''}
-              ORDER BY created_at DESC
-              LIMIT $2 OFFSET $3`,
-        values: [companyId, limit, offsets],
-      };
-    }
-
     const { rows } = await this._pool.query(query);
 
     return {
diff --git a/src/services/postgres/PurchasesService.js b/src/services/postgres/PurchasesService.js
index 68c9b74..f0d26c5 100644
--- a/src/services/postgres/PurchasesService.js
+++ b/src/services/postgres/PurchasesService.js
@@ -75,7 +75,7 @@ class PurchasesService {
               LEFT JOIN offices ON offices.id = purchases.office_id
               LEFT JOIN users ON users.id = purchases.created_by
               WHERE purchases.id = $1
-              ORDER BY created_at DESC`,
+              ORDER BY purchases.created_at DESC`,
       values: [purchaseId],
     };
 
diff --git a/src/services/postgres/SalesService.js b/src/services/postgres/SalesService.js
index f414396..3eeb7cb 100644
--- a/src/services/postgres/SalesService.js
+++ b/src/services/postgres/SalesService.js
@@ -73,7 +73,7 @@ class SalesService {
             WHERE 
               sales.office_id = (SELECT id FROM offices WHERE company_id = $1 LIMIT 1) 
             AND date::DATE BETWEEN $2 AND $3
-            ORDER BY created_at DESC`,
+            ORDER BY sales.created_at DESC`,
       values: [companyId, startDate, endDate],
     };
 
diff --git a/src/services/postgres/UnitsService.js b/src/services/postgres/UnitsService.js
index dc626ba..03f674a 100644
--- a/src/services/postgres/UnitsService.js
+++ b/src/services/postgres/UnitsService.js
@@ -26,8 +26,9 @@ class UnitsService {
       text: `
         SELECT id, name, description FROM units WHERE company_id = $1
         ${q !== null ? `AND name ILIKE '%${q}%'` : ''}
+        ORDER BY created_at DESC
         LIMIT $2 OFFSET $3
-        ORDER BY created_at DESC`,
+        `,
       values: [companyId, limit, offsets],
     };
 
diff --git a/src/validator/products/schema.js b/src/validator/products/schema.js
index 7cdd8a5..12e8817 100644
--- a/src/validator/products/schema.js
+++ b/src/validator/products/schema.js
@@ -3,8 +3,8 @@ const Joi = require('joi');
 const PostProductPayloadSchema = Joi.object({
   name: Joi.string().required(),
   description: Joi.string().allow(''),
-  cost: Joi.number().required(),
-  price: Joi.number().required(),
+  cost: Joi.number().required().greater(0),
+  price: Joi.number().required().greater(Joi.ref('cost')),
   stock: Joi.number().required(),
   category_id: Joi.string().guid().required(),
 });