indexeddb
Khóa học miễn phí Using getAll() Functions nhận dự án làm có lương
IndexedDB – Using getAll() Function
In the previous sections, we only retrieved objects from the store one at a time. Now we can retrieve all the data or subsets of the object stores. The get all method returns all the objects in the object store using the getAll() function
Syntax
ObjectStore.getAll(optionalConstraint);
We can directly call getAll() to return all the objects stored in the object store or else we can specify an optional constraint for example red colored cars from a car database
Example
In the following example script, we are calling the getAll() method to return all the objects stored in the object store at once −
<!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"});
store.createIndex("branch_db",["branch"],{unique: false});
}
request.onsuccess = function(){
document.write("database opened successfully");
const db = request.result;
const transaction=db.transaction("bots","readwrite");
const store = transaction.objectStore("bots");
const branchIndex = store.index("branch_db");
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 query = branchIndex.getAll(["IT"]);
query.onsuccess = function(){
document.write("query",query.result);
}
transaction.oncomplete = function(){
db.close;
}
}
</script>
</body>
</html>
Output
database opened successfully
query (1) [{...}]
arg1:(1) [{...}]
0:{id: 1, name: ''jason'', branch: ''IT''}
length:1
[[Prototype]]:Array(0)
[[Prototype]]:Object
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