Indexeddb 简明教程
IndexedDB - Deleting Data
在许多情况下，我们需要从数据库中删除数据，无论是出于存储目的，还是只是为了删除不想保留的数据以释放空间。如果我们希望从数据库中删除此不必要的数据，则可以使用 .delete() 函数。
There are many situations where we need to delete data from the database; be it for storage purposes or just removing unwanted data to free up space. If we want to delete this unnecessary data from a database we can use the .delete() function
Syntax
const request = objectStore.delete(data);我们使用 delete() 函数删除不需要的数据库字段。
We use the delete() function to delete the fields of the database which are not required.
Example
我们来看一个用于删除数据的示例脚本 −
Let us look at an example script to delete data −
<!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>