Is it wrong to open multiple database connections in indexedDB?

Question

I worked a bit with IndexedDB, and I can successfully create a new database, create a repository, and add a value during the “update needed”. What I don’t understand is the database remains open, or do you need to re-open it inside every function that needs read / write access to the information in the database?

For example, here is my code (which works) to create a new database and insert one record:

$(document).ready(function() {

var db;

function initDB() {
    console.log("opening db...");

    var req = indexedDB.open(dbName, version);
    req.onsuccess = function(event) {
      db = this.result;
      console.log("opening db is done");
    }

    req.onerror = function(event) {
      console.log("error opening db: ", event.target.errorCode);
    }

    req.onupgradeneeded = function(event) {
      db = event.target.result;
      var store = db.createObjectStore("creds", { autoincrement: true });
      store.add({ username:'none', password:'none'}, 1);
    }
  }

Which causes me confusion, when I need to access records in this database or add more records or delete records, I thought I could just create a new function and insert some values. This is what I have (which fails):

  function saveCreds() {
    usr = $("#username").val();
    psw = $("#password").val();

    $.getJSON(baseURL + "cred-check/?callback=?", { username:usr, password:psw }, function(data) {
      if (data.creds_good == 'true'); {
        // NEXT LINE FAILS
        var store = db.transaction(['creds'], 'readwrite').objectStore('creds');
        var request = store.get(1);
        request.onsuccess = function (event) {
          var data = request.result;
          data.username = usr;
          data.password = psw;

          var requestUpdate = store.put(data, 1);
          requestUpdate.onerror = function(event) {
            console.log("error putting value...");
          }
        }
      }
    });
  }

saveCreds initDB $(document).ready(), db ​​ initDB saveCreds, $(document).ready(), , .

, db undefined. : Cannot call method "transaction" of undefined.

, , , , / ?

Answer 1

: . , . . - db . javascript, indexedDB. . , - .

, , , :

function domultiplethings() {
  var db = ... 
  callfunction1(db);
  callfunction2(db);
}

function callfunction1(db) {
  if(!db) {
    // open a new connection then call ourself
  } else {
    // active connection, do read/write stuff
  }
}