摘要：網(wǎng)上搜來一堆，，幾乎沒有找到滿意的答案，經(jīng)過匯總并結(jié)合自己的理解，封裝了一套簡單的是一個(gè)異步對(duì)象，必須使用回調(diào)函數(shù)方式進(jìn)行調(diào)用打開一個(gè)數(shù)據(jù)庫，支持兩個(gè)參數(shù)，第二個(gè)參數(shù)指定版本號(hào)，我沒用到，讓瀏覽器自己創(chuàng)建版本號(hào)。

網(wǎng)上搜來一堆a(bǔ)pi，demo，幾乎沒有找到滿意的答案，經(jīng)過匯總并結(jié)合自己的理解，封裝了一套簡單的api

// indexedDB是一個(gè)異步對(duì)象，必須使用回調(diào)函數(shù)方式進(jìn)行調(diào)用

//打開一個(gè)數(shù)據(jù)庫，open支持兩個(gè)參數(shù)，第二個(gè)參數(shù)指定版本號(hào)，我沒用到，讓瀏覽器自己創(chuàng)建版本號(hào)。
var request = indexedDB.open("myDbName");
request.onsuccess = function(e) {
    //拿到db對(duì)象
    var db = e.target.result;
    
    
    //新增一個(gè)數(shù)據(jù)表：給數(shù)據(jù)表指定一個(gè)搜索的鍵值
    var store = db.createObjectStore("myTableName", {keyPath: "mykey"});
    
    
    // 創(chuàng)建數(shù)據(jù)庫事務(wù)（不是很理解事務(wù)二字），我理解的是：指定一個(gè)即將用來讀寫的數(shù)據(jù)
    //除了新建數(shù)據(jù)表都用這一行代碼 和上面的createObjectStore不能同時(shí)使用
    var transaction = db.transaction("myTableName", "readwrite").objectStore("myTableName");
    //到此，就可以進(jìn)行數(shù)據(jù)庫的數(shù)據(jù)表操作了
    
    
    //以下四個(gè)方法不是同時(shí)使用的，是分別封裝在不同方法內(nèi)的，這里為了演示，全部寫一起了
    
    //增：增加一條數(shù)據(jù) add(anything)
    //一般情況下不用add，而是用put方法
    var result = store.add({name:"mykey",value:"test1"});
    
    //刪：刪除一條數(shù)據(jù) delete(keyPath)
    var result = store.delete("mykey");
    
    //改：修改一條數(shù)據(jù)，一般情況下put使用比較多
    var result = store.put({name:"mykey",value:"test value"});
    
    //查：讀取一條數(shù)據(jù)
    var result = store.get("mykey");
    
    
    result.onsuccess = function(e) {
        //如果是get，這里就是讀取的數(shù)據(jù)
        var obj = e.target.result;
        success(obj);
    };
    result.onerror = function(e) {
    };
}
request.onerror = function() {
};

以下是我自己封裝好的方法：

var myDb = {
    options:{
        dbName:"myDbName",
        tbName:"myTableName",
        keyPath:"name",
    },
    getIndexedDB: function(name) {
        var that = this;
        return new Promise(function(success, error) {
            // 打開數(shù)據(jù)庫
            var request = indexedDB.open(that.options.dbName);
            request.onsuccess = function(e) {
                var database = e.target.result;
                // 操作數(shù)據(jù)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);
            };
            // 數(shù)據(jù)庫不存在時(shí)，或者版本號(hào)不一致時(shí)，就會(huì)執(zhí)行這里
            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) {
            // 打開數(shù)據(jù)庫
            var request = indexedDB.open(that.options.dbName);
            request.onsuccess = function(e) {
                var database = e.target.result;
                // 操作數(shù)據(jù)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);
            };
            // 數(shù)據(jù)庫不存在時(shí)，或者版本號(hào)不一致時(shí)，就會(huì)執(zhí)行這里
            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) {
            // 打開數(shù)據(jù)庫
            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)
            };
            // 數(shù)據(jù)庫不存在時(shí)，或者版本號(hào)不一致時(shí)，就會(huì)執(zhí)行這里
            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) {
            // 打開數(shù)據(jù)庫
            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)
            }
            // 數(shù)據(jù)庫不存在時(shí)，或者版本號(hào)不一致時(shí)，就會(huì)執(zhí)行這里
            request.onupgradeneeded = function(e) {
                e.target.result.createObjectStore(that.options.tbName, { keyPath: that.options.keyPath });
            };
        });
    }
};

測試一下：

//設(shè)置數(shù)據(jù)庫名稱和表名
myDb.options.dbName = "file_list";
myDb.options.tbName = "files";

//保存一條數(shù)據(jù)：
myDb.saveOneIndexedDB({
    name:"test",
    file:"123123",
}).then(function(file){
    /**file:{
        name:"test",
        file:"123123",
    }*/
});

//讀取數(shù)據(jù)
myDb.getIndexedDB("ex_zh.js").then(function(v){console.log(v)});