5. 文件上传下载 与 db数据库
文件上传
formidable
multer
npm i formidable multer
如何使用见： https://www.npmjs.com/
util.inspect 自己查
文件上传：表单必须有2个东西
1、enctyp="multipart/form-data"
2、method="post"
文件下载：
res.download(__filename);
formidable
server1.js
var http = require("http");
var formidable = require("formidable");
var fs = require("fs");
var path = require("path");
http.createServer(function(req,res){
console.log(req.url);
if(req.url == "/upload"){
var form = new formidable.IncomingForm();
form.uploadDir = "upload";
form.parse(req, function(err, fields, files) {
console.log(fields, files);
var oFile = files.f1;
var oldPath = oFile.path;
var newName = oldPath + oFile.name;
fs.rename(oldPath,newName,function(err){
res.writeHead(200,{'Content-Type':'text/html;charset=utf-8'});//设置response编码为utf-8
if(err){
res.end("上传失败");
} else {
res.end("上传成功");
}
});
});
}
}).listen(9000);
form.html
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
</head>
<body>
<form action="http://localhost:9000/upload" enctype="multipart/form-data" method="post">
<input type="text" name="user" value="aaa" /> <br /><br />
<input type="file" name="f1" value="" /> <br /><br />
<input type="submit"/>
</form>
</body>
</html>
res:
$ node server
/upload
{ user: 'aaa' } { f1:
File {
domain: null,
_events: {},
_eventsCount: 0,
_maxListeners: undefined,
size: 5,
path: 'upload\\upload_df6a908be04c7a08d5406784cfbcb468',
name: 'test.txt',
type: 'text/plain',
hash: null,
lastModifiedDate: 2018-07-13T12:55:25.753Z,
_writeStream:
WriteStream {
_writableState: [Object],
writable: false,
domain: null,
_events: {},
_eventsCount: 0,
_maxListeners: undefined,
path: 'upload\\upload_df6a908be04c7a08d5406784cfbcb468',
fd: null,
flags: 'w',
mode: 438,
start: undefined,
autoClose: true,
pos: undefined,
bytesWritten: 5,
closed: true } } }
server.js
var express = require("express");
var multer = require("multer");
var fs = require("fs");
var app = express();
app.listen(9000);
app.use(express.static("www"));
app.use(express.urlencoded({extended:false}));
//文件上传中间件
var multerMiddleware = multer().any();
app.use(multerMiddleware);
app.use("/upload",function(req,res){
console.log(req.files);
var oFile = req.files[0];
var path = "upload/"+ oFile.originalname;
var buf = oFile.buffer;
fs.writeFileSync(path,buf);
});
res:
$ node server2
[ { fieldname: 'f1',
originalname: 'test.txt',
encoding: '7bit',
mimetype: 'text/plain',
buffer: <Buffer 36 36 36 36 36>,
size: 5 } ]
文件下载download
var express = require("express");
var app = express();
app.listen(9000);
app.use("/download",function(req,res){
res.download(__filename);//下载自己
});
res:
db数据库
mysql与 mongodb
1.mysql
npm i mysql 驱动
连接数据库
var db = mysql.createConnection({
host,user,password,database
});
操作数据库:
db.query(sql,fn(err,data){...});
关闭数据库:
db.end(); 不是close();
//查询
select * from user_table;
select * from user_table where username="aaa" and password="123";
插入
insert into user_table(username,password) values("aaa","123");
2.mongodb
mysql mongodb —— json
关系型数据库 非关系型数据库
库 database database
表 table collection集合
行 row document文档
列 col field属性
安装目录： C:\Program Files\MongoDB\Server\3.3\bin
mongod 服务器端
mongo 客户端
配置环境变量：
;C:\Program Files\MongoDB\Server\3.3\bin
执行:
mongod --dbpath C:\data\db 默认的配置 以后启动 mogod
mongod --dbpath C:\mongoData 每次启动服务器必须带上完整路径
常用命令：
show dbs显示所有数据 —— 只显示有数据的库名称 show databases
db 查看用户当前所在的数据库
use 切换数据库、创建数据库
插入数据
db.user.insert({a:1}); 包括创建表 和 插入数据
db.user.insertOne( { x: 1 } );
db.user.find();
db.user.find({x:1});
select * from user_table where x="1"
use 20180713
db.user_table.insert({username:"aaa",password:"123",age:1});
db.user_table.insert({username:"aaa1",password:"123",age:18});
db.user_table.insert({username:"aaa2",password:"123",age:30});
db.user_table.insert({username:"aaa3",password:"123",age:60});
db.user_table.find({},{username:0/1,"_id":0});
select password from user_table
db.getCollection("user_table").find();
db.user_table.find().pretty() 美化json
show collections 查询当前库里面所有的表
db.user_table.find( { age: { $gt: 18 } } ,{"_id":0}) >
db.user_table.find( { age: { $gte: 18 } } ,{"_id":0}) >=
db.user_table.find( { age: { $lt: 18 } } ,{"_id":0}) <
db.user_table.find( { age: { $lte: 18 } } ,{"_id":0}) <=
db.user_table.find( {age:{ $gt: 18, $lt: 60 }},{"_id":0}) >18 <60
db.user_table.find({},{"_id":0}).sort( { age: -1 } ); 1 -1
1 :降序 desc
-1：升序 asc
db.user_table.find({},{"_id":0}).limit(2)
db.user_table.find({},{"_id":0}).limit(2).skip(0)
limit(pageSize).skip(beginIndex);
beginIndex = pageSize*(pageNo-1)
pageSize 2条
pageNo beginIndex
1 0
2 2
3 4
4 6
11条数据 每页2条 一共几页? Math.ceil(total/pageSize);
db.user_table.count();
db.collection.insert(
)
db.collection.insertOne(
) 同 insert
db.collection.insertMany([ <document 1> , <document 2>, ... ])
db.user_table.insertMany([
{username:"xxx1",password"xxx1",age:1},
{username:"xxx2",password"xxx2",age:2},
{username:"xxx3",password"xxx3",age:3}
]);
db.user_table.insertMany([
{username:"xxx1",password:"xxx1",age:1},
{username:"xxx2",password:"xxx2",age:2},
{username:"xxx3",password:"xxx3",age:3}
]);
db.user_table.insert([
{username:"xxx11",password:"xxx1",age:1},
{username:"xxx22",password:"xxx2",age:2},
{username:"xxx33",password:"xxx3",age:3}
]);
update
$set：修改或者添加
db.user_table.update(
{ username: "aaa" },
{
$set: {username: "AAA", password: "AAA",age: 100}
}
)
db.user_table.update( { username: "AAA" }, { $unset: { password: 1 } } )
$unset 删除属性
db.user_table.find({},{"_id":0});
db.user_table.update(
{ username: "aaa1" },
{ $set: { username : "AAA1" } },
{ multi: true} 可以修改多条数据 默认是false
)
db.user_table.updateOne(
{ username: "aaa3" },
{ $set: { username : "AAA3" } }
);
db.user_table.updateMany(
{ username: "aaa2" },
{ $set: { username : "AAA2" } }
);
删除 没有delete 用remove
db.user_table.deleteOne( { "_id" : ObjectId("5b48548b86ffbcc901fc4ac2") } );
db.user_table.deleteOne( { "age" : {$gte:1}} );
db.user_table.deleteMany( { "age" : {$gte:1}} );
db.user_table.remove( { "age" : {$gte:1}} );
db.user_table.remove( { "age" : {$gte:1}},{justOne:true} );
justOne:true 只删除一条 默认false删除所有
注意：必须在cmd环境下运行
导入数据：
mongoimport --db 20180713 --collection user_table --drop --file xxx.txt
导出数据
mongoexport --db 20180713 --collection user_table --out xxx.txt
xxx.txt
{username:"xxx1",password:"xxx1",age:1}
{username:"xxx2",password:"xxx2",age:2}
{username:"xxx3",password:"xxx3",age:3}
mongodb&& node
npm i mongodb
使用方法：https://www.npmjs.com/package/mongodb
mongodb浏览器的可视化
adminMongo https://github.com/mrvautin/adminMongo
mongoose:
mongodb/mongoose
DOM 文档对象模型
ODM 对象文档模型
npm i mongoose
https://www.npmjs.com/package/mongoose
db.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
mongoose.connect('mongodb://localhost/20180716');
//定义表结构的数据类型
var userSchema = new Schema({
user:String,
pass:String
});
//定义表 表结构都会带s,只能有一个s 控制台查询:db.user_tables.find();
var UserModel = mongoose.model('user_table', userSchema);
//创建数据 行 document
var oUser = new UserModel({user:"bbb"});
oUser.pass = "123";
//db.user_table.insert(document);
//插入
oUser.save(function (err, result) {
console.log(err, result);
//查询
//find
UserModel.find(function (err, data) {
console.log(err, data);
})
});
res:
$ node db.js
(node:9996) DeprecationWarning: current URL string parser is deprecated, and wil
l be removed in a future version. To use the new parser, pass option { useNewUrl
Parser: true } to MongoClient.connect.
null { _id: 5b4c780013c2a1270cd6c0fd,
user: 'bbb',
pass: '123',
__v: 0 }
null [ { _id: 5b4c76c859b0432a1c4e0626,
user: 'bbb',
pass: '123',
__v: 0 },
{ _id: 5b4c780013c2a1270cd6c0fd,
user: 'bbb',
pass: '123',
__v: 0 } ]
db2.js
连接成功测试
/*var mongoose = require('mongoose');
var Schema = mongoose.Schema;
mongoose.connect('mongodb://localhost/716');
var db = mongoose.connection;
db.on('error', function() {
console.log("连接失败");
});
db.once('open', function() {
console.log("连接已经建立");
});*/
//或者
/*var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/20180716',function(err) {
if(err){
console.log("连接失败");
} else {
console.log("连接已经建立");
}
});*/
res:
$ node db2
(node:11436) DeprecationWarning: current URL string parser is deprecated, and wi
ll be removed in a future version. To use the new parser, pass option { useNewUr
lParser: true } to MongoClient.connect.
连接已经建立
