本地查询网页数据库

if (localStorage.length >= 5 * 1024 * 1024) {
    alert("LocalStorage已满，请清理空间。");
} else {
    localStorage.setItem('key', 'value');
}

let request = indexedDB.open('myDatabase', 1);

request.onupgradeneeded = function(event) {
    let db = event.target.result;
    let objectStore = db.createObjectStore('myStore', { keyPath: 'id' });
};

request.onsuccess = function(event) {
    let db = event.target.result;
    let transaction = db.transaction(['myStore'], 'readwrite');
    let objectStore = transaction.objectStore('myStore');

    let request = objectStore.add({ id: 1, name: 'John' });

    request.onsuccess = function(event) {
        console.log("数据添加成功");
    };

    transaction.oncomplete = function(event) {
        db.close();
    };
};