IndexedDB - 删除数据
有很多情况我们需要从数据库中删除数据； 无论是出于存储目的还是只是删除不需要的数据以释放空间。 如果我们想从数据库中删除这些不必要的数据，我们可以使用 .delete() 函数
语法
const request = objectStore.delete(data);
我们使用delete()函数删除数据库中不需要的字段。
示例
让我们看一个删除数据的示例脚本 −
<!DOCTYPE html>
<html lang="en">
<head>
<title>Document</title>
</head>
<body>
<script>
const request = indexedDB.open("botdatabase",1);
request.onupgradeneeded = function(){
const db = request.result;
const store = db.createObjectStore("bots",{ keyPath: "id"});
}
request.onsuccess = function(){
document.write("database opened successfully");
const db = request.result;
const transaction=db.transaction("bots","readwrite");
const store = transaction.objectStore("bots");
store.add({id: 1, name: "jason",branch: "IT"});
store.add({id: 2, name: "praneeth",branch: "CSE"});
store.add({id: 3, name: "palli",branch: "EEE"});
store.add({id: 4, name: "abdul",branch: "IT"});
store.put({id: 4, name: "deevana",branch: "CSE
const deletename = store.delete(1);
deletename.onsuccess = function(){
document.write("id : 1 has been deleted");
}
transaction.oncomplete = function(){
db.close;
}
}
</script>
</body>
</html>
输出
database opened successfully id : 1 has been deleted
删除id后的数据库:1=
0 2
{id: 2, name: 'praneeth', branch: 'CSE'}
1 3
{id: 3, name: 'palli', branch: 'EEE'}
2 4
{id: 4, name: 'deevana', branch: 'CSE'}
