diff --git a/server/db/database.js b/server/db/database.js
index d38abb2..a0dbeed 100644
--- a/server/db/database.js
+++ b/server/db/database.js
@@ -144,7 +144,7 @@ export default class DBAdapter {
         }
     }
 
-    async deleteOrdersByIds(orderIds) {
+    async clearOrders(orderIds) {
         if (!orderIds || orderIds.length === 0) {
             console.log("No orders to delete");
             return;
@@ -165,4 +165,199 @@ export default class DBAdapter {
             return Promise.reject();
         }
     }
+
+    async changeOrderInfo({ id, customer_name, orderDate }){
+        if (!id) {
+            return Promise.reject({
+                type: DB_USER_ERROR,
+                error: new Error("Order ID is required")
+            });
+        }
+
+        const currentDate = await getCurrentDate();
+        if (orderDate < currentDate) {
+            return Promise.reject({
+                type: DB_USER_ERROR,
+                error: new Error("Order date cannot be less than current date")
+            });
+        }
+
+        try {
+            const order = await this.#dbClient.query('SELECT * FROM orders WHERE id = ?', [id]);
+
+            if (!order){
+                return Promise.reject({
+                    type: DB_USER_ERROR,
+                    error: new Error("Order not found")
+                });
+            }
+            
+            const updatedName = customer_name;
+            const updatedDate = orderDate;
+
+            await this.#dbClient.query('UPDATE orders SET customer_name = ?, order_date = ? WHERE id = ?',
+                [updatedName, updatedDate, id]
+            );
+
+        } catch(err){
+            return Promise.reject({
+                type: DB_INTERNAL_ERROR,
+                error: new Error("Server error")
+            });
+        }
+    }
+
+    async deleteOrderById(order_id){
+        try {
+            const orderItems = await this.#dbClient.query(
+                `SELECT product_id, quantity FROM order_items WHERE order_id = ?`,
+                [order_id]
+            );
+
+            for (const item of orderItems){
+                await this.#dbClient.query('UPDATE products SET quantity = quantity + ? WHERE id = ?', 
+                    [item.quantity, item.product_id]
+                );
+            }
+            await this.#dbClient.query(
+                `DELETE FROM orders WHERE id = ?`,
+                [order_id]
+            );
+        } catch(err){
+            return Promise.reject({
+                type: DB_INTERNAL_ERROR,
+                error: new Error("Server error")
+            });
+        }
+    }
+
+    async addOrderItem({ orderId, productId, quantity }){
+        await this.#dbClient.query('BEGIN');
+        try {
+            const product = await this.#dbClient.query(
+                'SELECT quantity FROM products WHERE id = ?', [productId]
+            );
+
+            // TODO
+            if (!product || product.quantity < quantity){
+                return Promise.reject();
+            }
+
+            const result = await this.#dbClient.query(
+                'INSERT INTO order_items (order_id, product_id, quantity) VALUES (?, ?, ?)',
+                [orderId, productId, quantity]
+            );
+
+            await this.#dbClient.query(
+                'UPDATE products SET quantity = quantity - ? WHERE id = >',
+                [quantity, productId]
+            );
+
+            await this.#dbClient.query('COMMIT');
+        } catch (err){
+            await this.#dbClient.query('ROLLBACK');
+            return Promise.reject();
+        }
+    }
+
+    async updateOrderItem({ itemId, quantity }){
+        await this.#dbClient.query('BEGIN');
+        try {
+            const item = await this.#dbClient.query(
+                'SELECT product_id, quantity FROM order_items WHERE id = ?', [itemId]
+            );
+
+            // TODO
+            if (!item){
+                return Promise.reject();
+            }
+
+            const diff = quantity - item.quantity;
+
+            if (diff > 0){
+                const product = await this.#dbClient.query(
+                'SELECT quantity FROM products WHERE id = ?', [item.productId]
+                );
+
+                if (product.quantity < diff){
+                    return Promise.reject();
+                }
+                
+                await this.#dbClient.query(
+                    'UPDATE products SET quantity = quantity - ? WHERE id = >',
+                    [diff, item.productId]
+                );
+            }
+
+            if (diff < 0) {
+                await this.#dbClient.query(
+                    'UPDATE products SET quantity = quantity - ? WHERE id = >',
+                    [-diff, item.productId]
+                );                
+            }
+
+            await this.#dbClient.query(
+                'UPDATE order_items SET quantity = ? WHERE id = >',
+                [quantity, itemId]
+            );                
+
+            await this.#dbClient.query('COMMIT');
+        } catch (err){
+            await this.#dbClient.query('ROLLBACK');
+            return Promise.reject();
+        }
+    }
+
+    async deleteOrderItem(itemId){
+        await this.#dbClient.query('BEGIN');
+        try {
+            const item = await this.#dbClient.query(
+                'SELECT product_id, quantity FROM order_items WHERE id = ?', [itemId]
+            );
+
+            // TODO
+            if (!item){
+                return Promise.reject();
+            }
+
+            await this.#dbClient.query(
+                'UPDATE products SET quantity = quantity + ? WHERE id = >',
+                [item.quantity, item.productId]
+            );
+
+            await this.#dbClient.query(
+                'DELETE FROM order_items WHERE id = ?',
+                [itemId]
+            );
+
+            await this.#dbClient.query('COMMIT');
+        } catch (err){
+            await this.#dbClient.query('ROLLBACK');
+            return Promise.reject();
+        }
+    }
+
+    async moveOrderItem( {itemId, targetOrderId }){
+        await this.#dbClient.query('BEGIN');
+        try {
+            const item = await this.#dbClient.query(
+                'SELECT id, order_id FROM order_items WHERE id = ?', [itemId]
+            );
+
+            // TODO
+            if (!item){
+                return Promise.reject();
+            }
+
+            await this.#dbClient.query(
+                'UPDATE order_items SET order_id = ? WHERE id = >',
+                [targetOrderId, itemId]
+            );
+
+            await this.#dbClient.query('COMMIT');
+        } catch (err){
+            await this.#dbClient.query('ROLLBACK');
+            return Promise.reject();
+        }
+    }
 }
\ No newline at end of file
diff --git a/server/server.js b/server/server.js
index 61e53c2..d5d2d26 100644
--- a/server/server.js
+++ b/server/server.js
@@ -72,7 +72,7 @@ app.post('/api/current-date/advance', async (req, res) => {
     try {
         const raw_ids = await adapter.getOrdersByDate(currentDate);
         const ids = raw_ids.map(item => item.id);
-        await adapter.deleteOrdersByIds(ids);
+        await adapter.clearOrders(ids);
 
         let nextDate = AddDays(currentDate, 1);
         await setCurrentDate(nextDate);
@@ -170,6 +170,115 @@ app.post('/api/orders', async (req, res) => {
     }
 });
 
+app.delete('/api/orders/:id', async (req, res) => {
+    try {
+        await adapter.deleteOrderById(req.params.id);
+        res.statusCode = 200;
+        res.message = "OK";
+        res.json({message: "success"});
+    } catch (err){
+        res.statusCode = 500;
+        res.message = "WHOOPS";
+        res.json({
+            timeStamp: new Date().toISOString(),
+            statusCode: 500,
+            error: `${err}`
+        });
+    }
+})
+
+app.post('/api/orders/:orderId/items', async (req, res) => {
+    let orderId = req.params.orderId;
+    let { productId, quantity } = req.body;
+    
+    try {
+        await adapter.addOrderItem({
+            orderId, 
+            productId,
+            quantity
+        });
+        
+        res.status(201).json({
+            orderId, 
+            productId,
+            quantity
+        });
+        
+    } catch (err) {
+        // TODO
+        res.status(500).json({
+            timeStamp: new Date().toISOString(),
+            statusCode: 500,
+        });
+    }
+});
+
+app.put('/api/orders/:orderId/items/:itemId', async (req, res) => {
+    let itemId = req.params.itemId;
+    let quantity = req.body.quantity;
+    
+    try {
+        await adapter.updateOrderItem({
+            itemId, 
+            quantity
+        });
+        
+        res.status(201).json({
+            itemId, 
+            quantity
+        });
+        
+    } catch (err) {
+        // TODO
+        res.status(500).json({
+            timeStamp: new Date().toISOString(),
+            statusCode: 500,
+        });
+    }
+});
+
+app.delete('/api/orders/:orderId/items/:itemId', async (req, res) => {
+    try {
+        await adapter.deleteOrderItem(req.params.itemId);
+        res.statusCode = 204;
+        res.message = "OK";
+        res.json({message: "success"});
+    } catch (err){
+        res.statusCode = 500;
+        res.message = "WHOOPS";
+        res.json({
+            timeStamp: new Date().toISOString(),
+            statusCode: 500,
+            error: `${err}`
+        });
+    }
+})
+
+app.post('/api/order-items/:itemId/move', async (req, res) => {
+    let itemId = req.params.itemId;
+    let targetOrderId = req.body.targetOrderId;
+    
+    try {
+        await adapter.moveOrderItem({
+            itemId, 
+            targetOrderId,
+        });
+        
+        res.status(201).json({
+            itemId, 
+            targetOrderId,
+        });
+        
+    } catch (err) {
+        // TODO
+        res.status(500).json({
+            timeStamp: new Date().toISOString(),
+            statusCode: 500,
+        });
+    }
+});
+
+
 app.use((req, res) => {
     res.status(404).json({ error: 'Invalid route' });
 });