const dbRequest = indexedDB.open('Eric')
dbRequest.onerror = function(err){
console.log('打开数据库失败~');
}
let db = null
dbRequest.onsuccess = function(event){
db = event.target.result
}
dbRequest.onupgradeneeded = function(event){
const db = event.target.result
// 创建一些存储对象
db.createObjectStore("users",{keyPath:"id"})
}
class User {
constructor(id,name,age){
this.id = id
this.name = name
this.age = age
}
}
const users = [
new User(100,"Eric",18),
new User(101,"kobe",40),
new User(102,"james",30),
]
const btns = document.querySelectorAll('button')
for(let i=0; i<btns.length; i++){
btns[i].onclick = function(){
// console.log(i);
const transaction = db.transaction("users","readwrite")
const store = transaction.objectStore("users")
switch(i){
case 0:
console.log('点击了新增');
for(const user of users){
const request = store.add(user)
request.onsuccess = function(){
console.log(`${user.name}插入成功`);
}
}
transaction.oncomplete = function(){
console.log('添加操作全部完成');
}
break
case 1:
console.log('点击了查询');
// 1 根据主键查询 索引
// const request = store.get(102)
// request.onsuccess = function(event){
// console.log(event.target.result);
// }
// 2 查询方式二
const request = store.openCursor()
request.onsuccess = function(event){
// console.log(event.target.result);
const cursor = event.target.result
if(cursor){
console.log(cursor.key,cursor.value);
cursor.continue()
} else {
console.log('查询完成');
}
}
break
case 2:
console.log('点击了删除');
const deleteRequest = store.openCursor()
deleteRequest.onsuccess = function(event){
const cursor = event.target.result
if(cursor){
if(cursor.key === 101){
cursor.delete()
}else{
cursor.continue()
}
} else {
console.log('查询完成');
}
}
break
case 3:
console.log('点击了修改');
const updateRequest = store.openCursor()
updateRequest.onsuccess = function(event){
const cursor = event.target.result
if(cursor){
if(cursor.key === 101){
const value = cursor.value
value.name = "curry"
cursor.update(value)
}else{
cursor.continue()
}
} else {
console.log('查询完成');
}
}
break
}
}
}
