html5 indexeddb的简明api

网上搜来一堆api，demo，几乎没有找到满意的答案，经过汇总并结合自己的理解，封装了一套简单的api

// indexedDB是一个异步对象，必须使用回调函数方式进行调用

//打开一个数据库，open支持两个参数，第二个参数指定版本号，我没用到，让浏览器自己创建版本号。
var request = indexedDB.open('myDbName');
request.onsuccess = function(e) {
    //拿到db对象
    var db = e.target.result;
    
    
    //新增一个数据表：给数据表指定一个搜索的键值
    var store = db.createObjectStore('myTableName', {keyPath: 'mykey'});
    
    
    // 创建数据库事务（不是很理解事务二字），我理解的是：指定一个即将用来读写的数据
    //除了新建数据表都用这一行代码 和上面的createObjectStore不能同时使用
    var transaction = db.transaction("myTableName", 'readwrite').objectStore("myTableName");
    //到此，就可以进行数据库的数据表操作了
    
    
    //以下四个方法不是同时使用的，是分别封装在不同方法内的，这里为了演示，全部写一起了
    
    //增：增加一条数据 add(anything)
    //一般情况下不用add，而是用put方法
    var result = store.add({name:'mykey',value:'test1'});
    
    //删：删除一条数据 delete(keyPath)
    var result = store.delete('mykey');
    
    //改：修改一条数据，一般情况下put使用比较多
    var result = store.put({name:'mykey',value:'test value'});
    
    //查：读取一条数据
    var result = store.get('mykey');
    
    
    result.onsuccess = function(e) {
        //如果是get，这里就是读取的数据
        var obj = e.target.result;
        success(obj);
    };
    result.onerror = function(e) {
    };
}
request.onerror = function() {
};

以下是我自己封装好的方法：

var myDb = {
    options:{
        dbName:'myDbName',
        tbName:'myTableName',
        keyPath:'name',
    },
    getIndexedDB: function(name) {
        var that = this;
        return new Promise(function(success, error) {
            // 打开数据库
            var request = indexedDB.open(that.options.dbName);
            request.onsuccess = function(e) {
                var database = e.target.result;
                // 操作数据表
                var store = database.transaction(that.options.tbName, 'readwrite').objectStore(that.options.tbName);
                var result = store.get(name);
                result.onsuccess = function(e) {
                    var obj = e.target.result;
                    success(obj);
                };
                result.onerror = function(e) {
                    error(obj);
                };
            }
            request.onerror = function() {
                error(event);
            };
            // 数据库不存在时，或者版本号不一致时，就会执行这里
            request.onupgradeneeded = function(e) {
                e.target.result.createObjectStore(that.options.tbName, { keyPath: that.options.keyPath });
            };
        });
    },
    getIndexedDBAll: function() {
        var that = this;
        return new Promise(function(success, error) {
            // 打开数据库
            var request = indexedDB.open(that.options.dbName);
            request.onsuccess = function(e) {
                var database = e.target.result;
                // 操作数据表
                var store = database.transaction(that.options.tbName, 'readwrite').objectStore(that.options.tbName);
                var cursorRequest = store.openCursor();
                var list = [];
                cursorRequest.onsuccess = function(event) {
                    var cursor = event.target.result;
                    if (cursor) {
                        var value = cursor.value;
                        list.push(value);
                        cursor.continue();
                    } else {
                        success(list);
                    }
                }
            }
            request.onerror = function() {
                error(event);
            };
            // 数据库不存在时，或者版本号不一致时，就会执行这里
            request.onupgradeneeded = function(e) {
                e.target.result.createObjectStore(that.options.tbName, { keyPath: that.options.keyPath });
            };
        });
    },
    saveOneIndexedDB: function(keyValue) {
        var that = this;
        return new Promise(function(success, error) {
            // 打开数据库
            var request = indexedDB.open(that.options.dbName);
            request.onsuccess = function(e) {
                var database = e.target.result;
                var store = null;
                store = database.transaction(that.options.tbName, 'readwrite').objectStore(that.options.tbName);
                var result = store.put(keyValue);
                result.onsuccess = function(event) {
                    success(keyValue);
                };
                result.onerror = function(event) {
                    error(event);
                };
            }
            request.onerror = function(event) {
                error(event)
            };
            // 数据库不存在时，或者版本号不一致时，就会执行这里
            request.onupgradeneeded = function(e) {
                var store = e.target.result.createObjectStore(that.options.tbName, { keyPath: that.options.keyPath });
                var result = store.put(keyValue);
                result.onsuccess = function(event) {
                    success(keyValue);
                };
                result.onerror = function(event) {
                    error(event);
                };
            };
        });
    },
    saveListIndexedDB: function(list, back, error) {
        var that = this;
        return Promise.all(list.map(function(v) {
            return that.saveOneIndexedDB(v);
        }));
    },
    deleteDB: function(name) {
        var that = this;
        return new Promise(function(success, error) {
            // 打开数据库
            var request = indexedDB.open(that.options.dbName);
            request.onsuccess = function(e) {
                var database = e.target.result;
                var store = database.transaction(that.options.tbName, 'readwrite').objectStore(that.options.tbName);
                var result = store.delete(name);
                result.onsuccess = function(event) {
                    success(name)
                };
                result.onerror = function(event) {
                    error(event)
                };
            }
            request.onerror = function(event) {
                error(event)
            }
            // 数据库不存在时，或者版本号不一致时，就会执行这里
            request.onupgradeneeded = function(e) {
                e.target.result.createObjectStore(that.options.tbName, { keyPath: that.options.keyPath });
            };
        });
    }
};

测试一下：

//设置数据库名称和表名
myDb.options.dbName = 'file_list';
myDb.options.tbName = 'files';

//保存一条数据：
myDb.saveOneIndexedDB({
    name:'test',
    file:'123123',
}).then(function(file){
    /**file:{
        name:'test',
        file:'123123',
    }*/
});

//读取数据
myDb.getIndexedDB('ex_zh.js').then(function(v){console.log(v)});