330 lines
9.4 KiB
JavaScript
330 lines
9.4 KiB
JavaScript
|
|
/**
|
|
*
|
|
* @param {*} dbName 数据库名称
|
|
* @param {*} version 数据库的版本
|
|
*/
|
|
function openDB(dbName, version = 1) {
|
|
return new Promise((resolve, reject) => {
|
|
var db; // 存储数据库对象
|
|
// 打开数据库，如果没有就是创建操作
|
|
var request = indexedDB.open(dbName, version);
|
|
|
|
// 数据库打开或者创建成功的时候
|
|
request.onsuccess = function (event) {
|
|
db = event.target.result;
|
|
console.log("数据库打开成功");
|
|
resolve(db);
|
|
}
|
|
|
|
// 打开失败
|
|
request.onerror = function () {
|
|
console.log("数据库打开失败");
|
|
}
|
|
|
|
// 数据库发生更新的时候
|
|
// 1. 版本号更新 2. 添加或者删除了表（对象仓库）的时候
|
|
// 当我们第一次调用 open 方法时，会触发这个事件
|
|
// 我们在这里来初始化我们的表
|
|
request.onupgradeneeded = function (event) {
|
|
console.log("数据库版本更新");
|
|
db = event.target.result;
|
|
// 创建数据仓库（表）
|
|
var objectStore = db.createObjectStore("stu", {
|
|
keyPath: "stuId", // 这是主键
|
|
autoIncrement: true // 实现自增
|
|
});
|
|
// 创建索引，有了索引之后，查询速度大大增快（类比新华字典）
|
|
objectStore.createIndex("stuId", "stuId", { unique: true });
|
|
objectStore.createIndex("stuName", "stuName", { unique: false });
|
|
objectStore.createIndex("stuAge", "stuAge", { unique: false });
|
|
}
|
|
})
|
|
}
|
|
|
|
/**
|
|
* 关闭数据库
|
|
* @param {object} db 数据库实例
|
|
*/
|
|
function closeDB(db) {
|
|
db.close();
|
|
console.log("数据库已关闭");
|
|
}
|
|
|
|
/**
|
|
* 删除数据库
|
|
* @param {object} dbName 数据库名称
|
|
*/
|
|
function deleteDBAll(dbName) {
|
|
console.log(dbName);
|
|
let deleteRequest = window.indexedDB.deleteDatabase(dbName);
|
|
deleteRequest.onerror = function (event) {
|
|
console.log("删除失败");
|
|
};
|
|
deleteRequest.onsuccess = function (event) {
|
|
console.log("删除成功");
|
|
};
|
|
}
|
|
|
|
|
|
/**
|
|
*
|
|
* @param {*} db 数据库实例
|
|
* @param {*} storeName 数据仓库实例（表）
|
|
* @param {*} data 要添加的数据
|
|
*/
|
|
function addData(db, storeName, data) {
|
|
var request = db.transaction([storeName], "readwrite")
|
|
.objectStore(storeName)
|
|
.add(data);
|
|
|
|
request.onsuccess = function () {
|
|
console.log("数据写入成功");
|
|
}
|
|
|
|
request.onerror = function () {
|
|
console.log("数据写入失败")
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 通过主键来读取数据
|
|
* @param {*} db 数据库实例对象
|
|
* @param {*} storeName 数据仓库（表）实例对象
|
|
* @param {*} key 主键
|
|
*/
|
|
function getDataByKey(db, storeName, key) {
|
|
return new Promise((resolve, reject) => {
|
|
var request = db.transaction([storeName])
|
|
.objectStore(storeName)
|
|
.get(key);
|
|
|
|
request.onsuccess = function () {
|
|
resolve(request.result)
|
|
}
|
|
|
|
request.onerror = function () {
|
|
console.log("数据查询失败");
|
|
}
|
|
})
|
|
}
|
|
|
|
/**
|
|
* 通过主键来读取数据
|
|
* @param {*} db 数据库实例对象
|
|
* @param {*} storeName 数据仓库（表）实例对象
|
|
*/
|
|
function getAllData(db, storeName) {
|
|
return new Promise((resolve, reject) => {
|
|
var request = db.transaction([storeName])
|
|
.objectStore(storeName)
|
|
.getAll();
|
|
|
|
request.onsuccess = function () {
|
|
resolve(request.result)
|
|
}
|
|
|
|
request.onerror = function () {
|
|
console.log("数据查询失败");
|
|
}
|
|
})
|
|
}
|
|
|
|
/**
|
|
* 通过游标（指针）来查询所有的数据
|
|
* @param {*} db
|
|
* @param {*} storeName
|
|
*/
|
|
function cursorGetData(db, storeName) {
|
|
return new Promise((resolve, reject) => {
|
|
var list = []; // 用于存放所有的数据
|
|
var request = db.transaction([storeName], "readwrite")
|
|
.objectStore(storeName)
|
|
.openCursor(); // 创建一个指针（游标）
|
|
|
|
request.onsuccess = function (event) {
|
|
var cursor = event.target.result;
|
|
// 查看游标（指针）有没有返回一条数据
|
|
if (cursor) {
|
|
list.push(cursor.value);
|
|
cursor.continue(); // 移动到下一条数据
|
|
} else {
|
|
resolve(list)
|
|
}
|
|
}
|
|
})
|
|
}
|
|
|
|
/**
|
|
* 根据索引来查询数据（只会返回一条）
|
|
* @param {*} db
|
|
* @param {*} storeName
|
|
* @param {*} indexName 索引名称
|
|
* @param {*} indexValue 索引值
|
|
*/
|
|
function getDataByIndex(db, storeName, indexName, indexValue) {
|
|
return new Promise((resolve, reject) => {
|
|
var request = db.transaction([storeName], "readwrite")
|
|
.objectStore(storeName)
|
|
.index(indexName)
|
|
.get(indexValue);
|
|
|
|
request.onsuccess = function (event) {
|
|
resolve(event.target.result);
|
|
}
|
|
})
|
|
}
|
|
|
|
/**
|
|
* 根据索引和游标来查询数据
|
|
* @param {*} db
|
|
* @param {*} storeName
|
|
* @param {*} indexName 索引名称
|
|
* @param {*} indexValue 索引值
|
|
*/
|
|
function getDataByIndex(db, storeName, indexName, indexValue) {
|
|
return new Promise((resolve, reject) => {
|
|
var list = []; // 存储所有满足条件的数据
|
|
var request = db.transaction([storeName], "readwrite")
|
|
.objectStore(storeName)
|
|
.index(indexName)
|
|
.openCursor(IDBKeyRange.lowerBound(indexValue));
|
|
|
|
request.onsuccess = function (event) {
|
|
var cursor = event.target.result;
|
|
if (cursor) {
|
|
list.push(cursor.value);
|
|
cursor.continue();
|
|
} else {
|
|
resolve(list);
|
|
}
|
|
}
|
|
})
|
|
}
|
|
|
|
/**
|
|
* 通过索引和游标分页查询记录
|
|
* @param {object} db 数据库实例
|
|
* @param {string} storeName 仓库名称
|
|
* @param {string} indexName 索引名称
|
|
* @param {string} indexValue 索引值
|
|
* @param {number} page 页码
|
|
* @param {number} pageSize 查询条数
|
|
*/
|
|
function cursorGetDataByIndexAndPage(
|
|
db,
|
|
storeName,
|
|
indexName,
|
|
indexValue,
|
|
page,
|
|
pageSize
|
|
) {
|
|
return new Promise((resolve, reject) => {
|
|
var list = []; // 用于存储当前页的分页数据
|
|
var counter = 0; // 创建一个计数器
|
|
var isPass = true; // 是否要跳过数据
|
|
var request = db.transaction([storeName], "readwrite")
|
|
.objectStore(storeName)
|
|
.openCursor(); // 创建一个指针（游标）对象（目前是指向第一条数据）
|
|
request.onsuccess = function (event) {
|
|
var cursor = event.target.result;
|
|
// 接下来有一个很重要的判断，判断是否要跳过一些数据
|
|
if (page > 1 && isPass) {
|
|
isPass = false;
|
|
cursor.advance((page - 1) * pageSize); // 跳过数据
|
|
return;
|
|
}
|
|
if (cursor) {
|
|
list.push(cursor.value);
|
|
counter++;
|
|
if (counter < pageSize) {
|
|
cursor.continue();
|
|
} else {
|
|
cursor = null;
|
|
resolve(list);
|
|
}
|
|
} else {
|
|
resolve(list)
|
|
}
|
|
}
|
|
})
|
|
}
|
|
|
|
/**
|
|
* 更新数据
|
|
* @param {object} db 数据库实例
|
|
* @param {string} storeName 仓库名称
|
|
* @param {object} data 数据
|
|
*/
|
|
function updateDB(db, storeName, data) {
|
|
return new Promise((resolve, reject) => {
|
|
var request = db.transaction([storeName], "readwrite")
|
|
.objectStore(storeName)
|
|
.put(data);
|
|
request.onsuccess = function () {
|
|
resolve({
|
|
status: true,
|
|
message: "更新数据成功"
|
|
})
|
|
}
|
|
})
|
|
}
|
|
|
|
/**
|
|
* 通过主键删除数据
|
|
* @param {object} db 数据库实例
|
|
* @param {string} storeName 仓库名称
|
|
* @param {object} id 主键值
|
|
*/
|
|
function deleteDB(db, storeName, id) {
|
|
return new Promise((resolve, reject) => {
|
|
var request = db
|
|
.transaction([storeName], "readwrite")
|
|
.objectStore(storeName)
|
|
.delete(id);
|
|
|
|
request.onsuccess = function () {
|
|
resolve({
|
|
status: true,
|
|
message: "删除数据成功"
|
|
})
|
|
};
|
|
|
|
request.onerror = function () {
|
|
reject({
|
|
status: true,
|
|
message: "删除数据失败"
|
|
})
|
|
};
|
|
})
|
|
}
|
|
|
|
|
|
/**
|
|
* 通过索引和游标删除指定的数据
|
|
* @param {object} db 数据库实例
|
|
* @param {string} storeName 仓库名称
|
|
* @param {string} indexName 索引名
|
|
* @param {object} indexValue 索引值
|
|
*/
|
|
function cursorDelete(db, storeName, indexName, indexValue) {
|
|
return new Promise((resolve, reject)=>{
|
|
var request = db.transaction([storeName], "readwrite")
|
|
.objectStore(storeName)
|
|
.index(indexName)
|
|
.openCursor(IDBKeyRange.only(indexValue));
|
|
request.onsuccess = function(event){
|
|
var cursor = event.target.result;
|
|
if(cursor){
|
|
var deleteRequest = cursor.delete();
|
|
deleteRequest.onsuccess = function(){
|
|
resolve({
|
|
status: true,
|
|
message: "删除数据成功"
|
|
})
|
|
}
|
|
cursor.continue();
|
|
}
|
|
}
|
|
})
|
|
} |