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Category: 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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