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Ich muss eine IndexedDB löschen und/oder löschen können, wenn der Benutzer auf meine Website zurückkehrt. Ich möchte, dass meine Datenbank jedes Mal neu ist, wenn ich mich anmelde.IndexedDB wie wird die Datenbank beim Einloggen gelöscht?
Wie lösche oder lösche ich alle Objektspeicher in einer Datenbank, wenn ich eine Seite direkt lade?
Irgendwelche Gedanken dazu, wie man das macht?
Code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>IndexedDB test</title>
<script type="text/javascript">
var indexedDB = window.indexedDB || window.webkitIndexedDB || window.mozIndexedDB || window.msIndexedDB;
var IDBTransaction = window.IDBTransaction || window.webkitIDBTransaction;
var db;
(function() {
var peopleData = [
{"FILENAME":"/NewDesigMemo1026732160521.pdf","DOC":"5/23/2016 | New Desig Memo","PRT_DT":"5/23/2016","EC":"","STATE":"","DES":"CIC","PRG_CODE":"","DIST":"","CNAME":""},
{"FILENAME":"/NewDesigMemo1026732160521.pdf","DOC":"5/23/2016 | New Desig Memo","PRT_DT":"5/23/2016","EC":"","STATE":"","DES":"CISR","PRG_CODE":"","DIST":"","CNAME":""},
{"FILENAME":"/AttendanceOutOfStateMemo102673220160521.pdf","DOC":"5/23/2016 | Attendance Out of State Memo","PRT_DT":"5/23/2016","EC":"","STATE":"","DES":"CISR","PRG_CODE":"","DIST":"","CNAME":""},
{"FILENAME":"/Attend1026732160521.pdf","DOC":"5/23/2016 | Attendance","PRT_DT":"5/23/2016","EC":"","STATE":"","DES":"CSRM","PRG_CODE":"","DIST":"","CNAME":""},
{"FILENAME":"/NewMemo1026732160521.pdf","DOC":"5/23/2016 | New Desig Memo","PRT_DT":"5/23/2016","EC":"","STATE":"","DES":"CRM","PRG_CODE":"","DIST":"","CNAME":""},
];
var peopleData2 = [
{"FILENAME":"/Attend102673220160312.pdf","PRT_DATE":"3/14/2016","EC":"","DOC":"3/14/2016 | CSRM Attendance","CRID":null,"PRG_CODE":"","STATE":"","DES":"","DATE_SENT":null,"PRG_DESC":null,"YEAR":null,"ISSUE":"","DIST":null,"CNAME":""},
{"FILENAME":"/RMagazine.aspx?I=r_spring_2016&P=1026732","PRT_DATE":"","EC":"","DOC":"R Magazine Spring 2016","CRID":null,"PRG_CODE":"","STATE":"","DES":"","DATE_SENT":null,"PRG_DESC":null,"YEAR":null,"ISSUE":"Spring 2016","DIST":null,"CNAME":""},
{"FILENAME":"/Packet+Notification+CISR+CIC+20160309ALM.html","PRT_DATE":"3/9/2016","EC":"20160317LLM","DOC":"3/9/2016 | Packet Notification","CRID":null,"PRG_CODE":"","STATE":"","DES":"","DATE_SENT":null,"PRG_DESC":null,"YEAR":null,"ISSUE":"","DIST":null,"CNAME":"WTH"},
{"FILENAME":"Eval20160317LLM1026732.pdf","PRT_DATE":"","EC":"20160317LLM","DOC":"Evaluation_Packet","CRID":null,"PRG_CODE":"ALM","STATE":"LA","DES":"","DATE_SENT":null,"PRG_DESC":null,"YEAR":null,"ISSUE":"","DIST":null,"CNAME":"WTH"},
{"FILENAME":"Eval20160315LPR1026732.pdf","PRT_DATE":"","EC":"20160315LPR","DOC":"Evaluation_Packet","CRID":null,"PRG_CODE":"PR","STATE":"LA","DES":"","DATE_SENT":null,"PRG_DESC":null,"YEAR":null,"ISSUE":"","DIST":null,"CNAME":"IPR"}
]
function initDb() {
var request = indexedDB.open("DocsDB", new Date().getUTCMilliseconds());
request.onsuccess = function (evt) {
db = request.result;
// Only do the below if this is first visit to page...
if(window.performance) {
if(performance.navigation.type == 0) {
var store = getObjectStore(db);
// The db already exists so delete it and re-create it so we don't have stale records.
if(store != null) {
store.clear();
}
}
}
};
request.onerror = function (evt) {
console.log("IndexedDB error: " + evt.target.error.code);
};
request.onupgradeneeded = function (evt) {
var objectStore = evt.currentTarget.result.createObjectStore(
"docs", { keyPath: "id", autoIncrement: true });
objectStore.createIndex("docname", "DOC", { unique: false });
objectStore.createIndex("printdate", "PRT_DT", { unique: false });
for (i in peopleData) {
objectStore.add(peopleData[i]);
}
};
}
function getObjectStore(db, mode) {
if(typeof db != 'undefined') {
var tx = db.transaction('docs', 'readwrite');
return tx.objectStore('docs');
} else {
return null;
}
}
function contentLoaded() {
initDb();
var btnPrint = document.getElementById("btnPrint");
btnAdd.addEventListener("click", function() {
var transaction = db.transaction("docs", "readwrite");
var objectStore = transaction.objectStore("docs");
for (i in peopleData2) {
var request = objectStore.add(peopleData[i]);
request.onsuccess = function (evt) {
// do something after the add succeeded
};
}
}, false);
btnPrint.addEventListener("click", function() {
var output = document.getElementById("printOutput");
output.textContent = "";
var transaction = db.transaction("docs", "readwrite");
var objectStore = transaction.objectStore("docs");
var request = objectStore.openCursor();
request.onsuccess = function(evt) {
var cursor = evt.target.result;
if (cursor) {
output.textContent += "id: " + cursor.key + " is " + cursor.value.FILENAME + " " + cursor.value.DOC;
cursor.continue();
}
};
}, false);
}
window.addEventListener("DOMContentLoaded", contentLoaded, false);
})();
</script>
</head>
<body>
<div id="container">
<input type="button" id="btnAdd" value="Add Records" />
<br />
<br />
<input type="button" id="btnPrint" value="Print objectStore" />
<br />
<br />
<output id="printOutput">
</output>
</div>
</body>
</html>
Könnte ich so etwas wie dies für die „Version“ verwenden: 'neue Date(). GetUTCMilliseconds() ' – MB34
Sie müssen den Objektspeicher im' onupgradeeneeded' erhalten, um es zu löschen/löschen, und zu diesem Zeitpunkt ist die Datenbank noch nicht geöffnet, so dass Sie den Objektspeicher nicht bekommen können. Wenn Sie das "evt.currentTarget.result" übergeben, um den Objektspeicher abzurufen, erhalten Sie einen Fehler, der versucht, die Transaktion zu verwenden, um es zu erhalten. 'var tx = db.transaction ('docs', 'readwrite'); Rückgabe tx.objectStore ('docs');': 'Fehler beim Ausführen von 'transaction' in 'IDBDatabase': Eine Versionswechseltransaktion läuft. ' – MB34
Code oben angezeigt. – MB34