八、路由 router

路由:router

用戶功能

/user ----> index.html

/user/login ----> login.html

/user/reg ----> reg.html

/user userRouter => express.Router();

app.use("/user",userRouter);

新聞功能

/news ----> index.html
/news/edit ----> edit.html
/news/add ----> add.html
router.js

var express = require("express");
var app = express();
app.listen(9000);

var userRouter = express.Router();
var newsRouter = express.Router();

// /user  /news

app.use("/user",userRouter);
app.use("/news",newsRouter);

userRouter.get("/",function(req,res){
    res.send("user--->index.html"); 
});

userRouter.get("/login",function(req,res){
    res.send("user--->login.html"); 
});

userRouter.get("/reg",function(req,res){
    res.send("user--->reg.html");   
});


newsRouter.get("/",function(req,res){
    res.send("news--->index.html"); 
});

newsRouter.get("/edit",function(req,res){
    res.send("user--->edit.html");  
});

newsRouter.get("/add",function(req,res){
    res.send("user--->add.html");   
});

---

express

Express 應用生成器

npm install express-generator -g

建立應用

express myapp -e

下載模塊

cnpm i

啓動服務:

npm start

node bin/www

npm run script名字

---

cnpm i -S cookie-session multer consolidate mysql

---

鏈接池：

mysql.createConnection({})
mysql.createPool({
connectionLimit:10默認是10條
})

---

app.js:

var createError = require("http-errors");
var logger = require("morgan");
var express = require("express");
var path = require("path");
var cookieParser = require("cookie-parser");
var cookieSession = require("cookie-session");
var consolidate = require("consolidate");
var multer = require("multer");

var indexRouter = require("./routes/index");
var usersRouter = require("./routes/users");

var app = express();

//文件上傳
var multerMiddleware = multer({dest:"upload"}).any();
app.use(multerMiddleware);

// 模板引擎
app.set("view engine", "html");
app.set("views", "views");
app.engine("html", consolidate.ejs);

//日誌
app.use(logger("dev"));

//處理post數據
app.use(express.json());
app.use(express.urlencoded({ extended: false }));

//cookie-session
app.use(cookieParser());


var keys = [];
for(var i = 0; i < 10000; i++){
    keys.push("sessionid"+Math.random());
}

app.use(cookieSession({
    name:"sid",
    keys,
    maxAge:30*60*1000 //ms
}));


//靜態服務器
app.use(express.static("public"));

app.use("/", indexRouter);
app.use("/users", usersRouter);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get("env") === "development" ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render("error");
});

module.exports = app;

users.js:

var express = require("express");
var pool = require("../utils/pool");
var md5 = require("../utils/md5");

var router = express.Router();

var pageSize = 10;

/* /users ---> index.html */
router.get("/", function(req, res) {

    if(!req.session.isLogin){
        res.redirect("/users/login");
    }

    var pageNo = req.query.pageNo || 1;
    //總頁數
    var totalSql = "select count(*) as count from user_table";
    pool.query(totalSql,function(err,data){
        console.log(data);
        if(data.length == 0){//沒有數據
            res.render("./users/index.html",{pageCount:0});
        } else {//有數據
            var count  = data[0].count;
            var pageCount = Math.ceil(count/pageSize);
            //作分頁
            var beginIndex = (pageNo-1)*pageSize;
            var querySql = `select * from user_table limit ${beginIndex},${pageSize}`;
            console.log(1111,querySql);
            pool.query(querySql,function(err,data){
                console.log(111,data,pageCount);
                res.render("./users/index.html",{data,pageCount,pageNo});
            });
        }
    });
});

//渲染頁面
router.get("/login", function(req, res) {
    res.render("./users/login2",{error:1,msg:""});
});

//處理接口
router.post("/login", function(req, res) {
    var {user,pass} = req.body;

    pass = md5(pass);
    
    var sql = `select * from user_table where username="${user}" and password="${pass}"`;
    pool.query(sql,function(err,data){
        
        if(data.length == 0){//用戶名或者密碼錯誤
            //res.send({error:0,msg:"用戶名或者密碼錯誤"});
            
            res.render("./users/login2",{error:0,msg:"用戶名或者密碼錯誤"});
        } else {
            //res.send({error:1,msg:"登錄成功"});

            req.session.isLogin = true;

            res.redirect("/");
        }   
    });
});



router.get("/reg", function(req, res) {
    res.render("./users/reg");
});
//處理接口
router.post("/reg", function(req, res) {
    var {user,pass} = req.body;
      
    pass = md5(pass);
    
    var querySql = `select * from user_table where username="${user}"`;
    pool.query(querySql,function(err,data){
        
        if(data.length == 0){//用戶不存在 能夠註冊
            var inserSql = `insert into user_table(username,password) values("${user}","${pass}")`
            pool.query(inserSql,function(err){
                res.send({error:1,msg:"註冊成功"}); 
            });
             
        } else {//用戶已經存在
            res.send({error:0,msg:"用戶已存在"});
        }   
    }); 
});

module.exports = router;

SSR

分頁:

select * from user_table; 查詢全部

每頁顯示10條數據 pageSize = 10;

select * from user_table limit beginIndex,pageSize;

select * from user_table limit 1,10;

頁數pageNo      beginIndex
    1            0  - 9
    2           10 - 19
    3           20 - 29

beginIndex = (pageNo-1)*pageSize

pageCount總頁數 = Math.ceil(總數據/每頁顯示多少條) = Math.ceil(count/pageSize)

count? ===> select count(*) as count from user_table;

---

get  --- req.query   /url?name=value  ----> /url?name=aaa
         req.params  /url/:name       ----> /url/aaa

post --- req.body