Add keys to react lists

src/order/OrderList.js

@@ -6,7 +6,7 @@ import Fetcher from "../Fetcher";
 function OrderList() {
   const [orders, setOrders] = useState([]);
   const order_list = orders.map((o) => (
-    <Card as={Col} sm={4}>
+    <Card key={o.ID} as={Col} sm={4}>
       <Card.Body>
         <Card.Title>{o.name}</Card.Title>
         <Card.Text>{o.description}</Card.Text>

src/transaction/MyTransactions.js

@@ -10,7 +10,7 @@ function MyTransactions() {
 
   const entries = transactions.map((transaction) => {
     return (
-      <TransactionTr transaction={transaction}>
+      <TransactionTr key={transaction.ID} transaction={transaction}>
         <td>{icon(transaction)}</td>
         <td>{printDate(transaction.date)}</td>
         <td>{printMoney(transaction.total) + " €"}</td>

src/transaction/TransactionList.js

@@ -43,7 +43,7 @@ function TransactionList() {
 
   const entries = transactions.map((transaction) => {
     return (
-      <TransactionTr transaction={transaction}>
+      <TransactionTr key={transaction.ID} transaction={transaction}>
         <td>{icon(transaction)}</td>
         <td>{printTransactionID(transaction)}</td>
         <td>{printDate(transaction.date)}</td>