indexedDB 增删改查基本操作
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title></title> <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script> <script src="./js/vue.min.js"></script> </head> <body> <div id="app"> <p>数据库名字:</p> <input placeholder="输入要打开的数据库名字" v-model="databaseName" /> <button @click="openMyDataBase(databaseName,version)">打开数据库</button> <button @click="readAll" :disabled="!db">遍历数据</button> <button @click="useIndex" :disabled="!db">使用索引</button> <button @click="clear" :disabled="!db">清空对象仓库</button> <p>主键:</p> <input placeholder="输入要读取数据的主键" type="number" v-model="primaryKey" /> <button @click="read" :disabled="!db">读取数据</button> <button @click="remove" :disabled="!db">删除数据</button> <p>要修改的属性:</p> <input v-model="obj.name" /> <input v-model="obj.age" /> <input v-model="obj.email" /> <button :disabled="!db" @click="updateDate">更新数据</button> <p>要插入对象的信息（插入位置是最后一行）:</p> <input v-model="obj.name" /> <input v-model="obj.age" /> <input v-model="obj.email" /> <button @click="addRecord(obj)" :disabled="!db">插入一条新数据</button> </div> </body> <script> var vm = new Vue({ el: "#app", data: { version: 1, databaseName: "test", db: null, request: null, primaryKey: 1, obj: { name: "张三", age: 22, email: "Zsan@foxmail.com" } }, methods: { openMyDataBase(databaseName, version) { var that = this; var db; this.request = window.indexedDB.open(databaseName, version); this.request.onupgradeneeded = function(e) { db = e.target.result; console.log("onupgrageneeded"); // 通常新建数据库以后，第一件事是新建对象仓库（即新建表），并设置主键 var objectStore; if (!db.objectStoreNames.contains(databaseName)) { //如果这个 对象仓库/表 不存在，就新建 objectStore = db.createObjectStore("person", { autoIncrement: true //指定主键为一个递增的整数 }); } /** * 新建当前数据库的索引 * 必须在VersionChange监听函数里调用 * objectStore.createIndex(indexName, keyPath, objectParameters) * indexName：索引名 * keyPath：主键 * objectParameters：配置对象（可选） * unique：如果设为 true，将不允许重复的值 * multiEntry：如果设为 true，对于有多个值的主键数组，每个值将在索引里面新建一个条目，否则主键数组对应一个条目。 * * */ objectStore.createIndex("name","name",{unique:false});//可以重复 objectStore.createIndex("age","age",{unique:false});//可以重复 objectStore.createIndex("email","email",{unique:true});//不能重复 } this.request.onsuccess = function(e) { db = that.request.result; that.db = db; console.log("success"); } this.request.onerror = function(e) { console.log("error"); } }, addRecord(obj) { var that = this; var db = that.db; var transaction = db.transaction(["person"], "readwrite"); //写入数据需要新建一个事务。新建时必须指定表格名称和操作模式（“只读”或“读写”） var objectStore = transaction.objectStore( "person"); //新建事务以后，通过IDBTransaction.objectStore(name)方法，拿到 IDBObjectStore 对象 this.obj.age = parseInt(this.obj.age); var request = objectStore.add(obj); //再通过表格对象的add()方法，向表格写入一条记录 request.onsuccess = function(e) { console.log("数据写入成功"); } request.onerror = function(e) { console.log("数据写入失败:",e.srcElement.error); } }, read() { var that = this; var db = that.db; var transaction = db.transaction(["person"]); var objectStore = transaction.objectStore("person"); var request = objectStore.get(parseInt(this.primaryKey)); //objectStore.get()方法用于读取数据，参数是主键的值。 request.onsuccess = function(e) { if (request.result) { var obj = { name: "", age: 0, email: "" }; obj.name = request.result.name; obj.age = request.result.age; obj.email = request.result.email; console.log("obj:", obj); that.obj = obj; } else { console.log("未获得数据记录"); } } request.onerror = function(e) { console.log("事务失败"); } }, readAll() { var that = this; var db = that.db; var transaction = db.transaction(["person"]); var objectStore = transaction.objectStore( "person"); objectStore.openCursor().onsuccess = function(e) { var cursor = e.target.result; var obj = { primaryKey: 1, name: "", age: 0, email: "" }; if (cursor) { obj.primaryKey = cursor.key; obj.name = cursor.value.name; obj.age = cursor.value.age; obj.email = cursor.value.email; console.log("obj:", obj); cursor.continue(); } else { console.log("没有更多数据了"); } } }, updateDate() { var that = this; var db = this.db; var objectStore = db.transaction("person", "readwrite").objectStore("person"); /** * 更新数据要使用IDBObject.put()方法。 * 第一个参数为新数据 * 第二个参数为主键，该参数可选，且只在自动递增时才有必要提供，因为那时主键不包含在数据值里面 * */ this.obj.age = parseInt(this.obj.age); var request = objectStore.put(this.obj, parseInt(this.primaryKey)); // var request = db.transaction(['person'], 'readwrite') // .objectStore('person') // .put({ id: 1, name: '李四', age: 35, email: 'lisi@example.com' }); //put()方法自动更新了主键为1的记录。 request.onsuccess = function(event) { console.log('数据更新成功'); }; request.onerror = function(event) { console.log('数据更新失败'); } }, remove() { var that = this; var db = this.db; console.log(this.primaryKey); var request = db.transaction("person", "readwrite").objectStore("person").delete(parseInt(this .primaryKey)); request.onsuccess = function(event) { console.log('数据删除成功'); }; }, useIndex() { var db = this.db; var objectStore = db.transaction("person","readonly").objectStore("person"); var index = objectStore.index("name"); var request = index.get("张三"); //只返回第一个 // var request = index.getAll("张三");//返回所有的 “张三” request.onsuccess = function(e){ var result = e.target.result; if(result){ console.log("result:",result); console.log("索引查询成功"); }else{ console.log("索引查询失败"); } } }, clear() { var db = this.db; var request = db.transaction("person", "readwrite").objectStore("person").clear(); request.onsuccess = function(e) { console.log("清空对象仓库成功"); } request.onerror = function(e) { console.log("清空仓库失败"); } } } }) </script> </html>
参考链接：
[1] https://www.shulanxt.com/doc/dbdoc/db-intro
[2] http://www.ruanyifeng.com/blog/2018/07/indexeddb.html
[3] https://wangdoc.com/javascript/bom/indexeddb.html
[4] https://www.bilibili.com/video/BV15J411H7GH
[5] https://developer.mozilla.org/zh-CN/docs/Web/API/IDBObjectStore
[6] https://zhuanlan.zhihu.com/p/399223337
