diff --git a/srv/orders-service.js b/srv/orders-service.js
index 222129b..5eeb9b2 100644
--- a/srv/orders-service.js
+++ b/srv/orders-service.js
@@ -8,7 +8,7 @@ class OrdersService extends cds.ApplicationService {
     this.before ('UPDATE', 'Orders', async function(req) {
       const { ID, Items } = req.data
       if (Items) for (let { product_ID, quantity } of Items) {
-        const { quantity:before } = await SELECT.one.from (OrderItems, oi => oi.quantity) .where ({up__ID:ID, product_ID})
+        const { quantity:before } = (await SELECT.one.from (OrderItems, oi => oi.quantity) .where ({up__ID:ID, product_ID})) || {quantity: 0}
         if (quantity != before) await this.orderChanged (product_ID, quantity-before)
       }
     })
diff --git a/test/odata.orders.test.js b/test/odata.orders.test.js
new file mode 100644
index 0000000..79378c6
--- /dev/null
+++ b/test/odata.orders.test.js
@@ -0,0 +1,34 @@
+const cds = require('@sap/cds')
+const { GET, POST, PATCH, expect, defaults } = cds.test(__dirname + "/../", '--with-mocks')
+
+describe ('OrdersService', () => {
+
+  beforeAll (()=> {
+    cds.requires.queue = { timeout: '1h' }
+    defaults.auth = { username: 'alice' }
+    defaults.path = '/odata/v4/orders'
+  })
+
+  it('check order count', async () => {
+    const { data } = await GET(`/Orders`, {
+      params: {
+        $select: 'OrderNo'
+      },
+    })
+    expect (data.value.length) .to.equal (2)
+  })
+
+  it('add new OrderItem to active Order', async () => {
+    const { data: data1 } = await POST(`/Orders`, {
+      'OrderNo': '3',
+      IsActiveEntity: true
+    })
+    expect (data1.OrderNo) .to.equal ('3')
+    const { data: data2 } = await PATCH(`/Orders(${data1.ID})`, {Items:[{
+      product_ID: '201',
+      quantity: 1
+    }]})
+    expect (data2.ID) .to.equal (data1.ID)
+  })
+
+})