未捕获的 DOMException：无法从“IDBRequest”读取“结果”属性：请求尚未完成

Question

I'm binding data to 3 dropdowns by calling a method from another file of javascript. The data source of dropdown loading from IndexedDB. Data binding JS,

function bindStateData(){
     getMstStates("#state");
     getMstStates("#drstate");
     getMstStates("#cstate");
   }

Database manager js,

function getMstStates(state) {
    var request = indexedDB.open('AppDatabase', '3')
    request.onsuccess = function (e) {
        var dbInstance = e.target.result;
        let transaction = dbInstance.transaction("MstStates", "readonly");
        const statesDetailsStore = transaction.objectStore("MstStates");
        stateData = statesDetailsStore.getAll();
        stateData.onsuccess = function () {
            var MstStatesMap = new Object();
            var len = stateData.result.length,
            i;
            for (i = 0; i < len; i++) {
                MstStatesMap[i] = {};
                MstStatesMap[i].StateId = stateData.result[i].StateId;
                MstStatesMap[i].StateName = stateData.result[i].StateName;
            }
            callBackOptionItems(MstStatesMap, state);
        }
        stateData.onerror = function () {
            console.log('getMstStates : ' + e);
        }
     }
    request.onerror = function (e) { console.log('getMstStates : ' + e); }
}

function callBackOptionItems(MstOptionMap, objID) {
    for (var j in MstOptionMap) {
        var k, v
        var tem = 0;
        for (var i in MstOptionMap[j]) {
            if (tem == 0) {
                k = MstOptionMap[j][i]
            } else {
                v = MstOptionMap[j][i];
            }
            tem++
        }
        var el = $(objID);
        $(el).append('<option value="' + k + '">' + v + '</option>');

    }
    if (objID == '#select-history') {
        $("#select-history").append('<option value="4">Other</option>');
    }
}

When I tried to loading data I got the following error,

Uncaught DOMException: Failed to read the 'result' property from 'IDBRequest': The request has not finished.
    at IDBRequest.stateData.onsuccess

The same code logic was written in WebSQL, it was running properly, but unfortunately from iOS 13 version websql support has been revoked.

Answer 1

I have resolved this issue. The main culprit line is,

var len = stateData.result.length;

The correct code is as follows,

    var _request = statesDetailsStore.getAll();
    _request.onsuccess = function (event) {
        var MstStatesMap = new Object();
        var stateData = event.target.result;
    }