mysql\mongodb\redis
1 数据库
持久化数据
Mongodb:json形式存储
安装必要的软件：mongodb + compass
database mongodb软件可以创建多个数据库
collection 集合 一组数据
document 文档 一条数据 json
field 字段 文档属性
数据导入数据库
mongoimport -d 数据库 -c 集合名 --file 导入的数据文件
基础应用
let mongoose = require(‘mongoose‘);
// 建立数据库连接
mongoose.connect(‘mongodb://localhost/demo1‘, { useNewUrlParser: true, useUnifiedTopology: true })
.then(() => {
console.log(‘数据库连接成功‘);
}).catch((err) => {
console.log(err);
});
//创建集合的规则
const teacherSchema = mongoose.Schema({
name: String,
tel: String,
age: Number
});
//创建符合规则的集合实例
const Teacher = mongoose.model(‘Teacher‘, teacherSchema); //数据库默认将数据库名后+s
//创建文档
Teacher.create({
name: ‘macro‘,
tel: ‘123456‘,
age: 25
}, (err, doc) => {
console.log(err);
console.log(doc);
});
mongoDB数据库查询
// 全表扫描
Teacher.find().then(res => {
console.log(res);
});
//通过id扫描
Teacher.find({ _id: ‘5eb74d758a8f28c0780f5fa0‘ }).then(res => {
console.log(res);
});
//通过姓名查找
Teacher.find({ name: ‘李鹤‘ }).then(res => {
console.log(res);
});
//查询第一个:默认返回集合中满足条件的第一条文档
Teacher.findOne({ name: ‘李鹤‘ }).then(res => {
console.log(res);
});
// 注意json格式书写
Teacher.find({ age: { $gte: 18, $lte: 30 } }).then(res => {
console.log(res);
});
//满足约束条件范围的结果集
//$in : 指代只要有一个就可以
Teacher.find({ hobbies: { $in: [‘篮球‘, ‘乒乓球‘] } }).then(res => {
console.log(res);
});
//查找所有学生的年龄和姓名
//-_id : 去掉id字段
Teacher.find().select(‘name age -_id‘).then(res => {
console.log(res);
});
//排序:默认升序
Teacher.find().sort(‘age‘).then(res => {
console.log(res);
});
//- 降序
Teacher.find().sort(‘-age‘).then(res => {
console.log(res);
});
//分页:skip(2):跳过前2条
// limit(2):最后两条
Teacher.find().skip(1).then(res => {
console.log(res);
});
//删除
Teacher.findOneAndDelete({ name: ‘macro‘ });
//返回：找到满足条件的数据并且删除
Teacher.findOneAndDelete({ _id: ‘5eb74d758a8f28c0780f5fa0‘ }).then(res => {
console.log(res);
}).catch(err => {
console.log(err);
});
//删除多条数据
Teacher.deleteMany({ name: ‘macro‘ }).then(res => {
console.log(res);
}).catch(err => {
console.log(err);
});
//修改
Teacher.updateOne({ name: ‘macro‘ }, { age: 19, tel: 98989 }).then(res => {
console.log(res);
});
//修改多条/
//{限制条件}
Teacher.updateMany({}, { age: 19, tel: 98989 }).then(res => {
console.log(res);
});
//数据校验
//创建集合的规则
const teacherSchema = mongoose.Schema({
name: {
type: String,
required: [true, ‘请传入姓名‘], //必传
minlength: [2, ‘姓名长度不能小于2‘],
maxlength: [9, ‘姓名长度不能大于9‘],
trim: true //去除字符串首尾空格
},
tel: String,
age: {
type: Number,
min: 1,
max: 126
},
hobbies: [String],
birthday: {
type: Date,
default: Date.now
},
email: {
type: String,
enum: {
values: [‘user@qq.com‘, ‘macro@163.com‘],
message: ‘邮箱地址必须从指定的选择‘
}
},
qq: {
type: String,
validate: {
validator: v => {
return v.charAt(0) === ‘1‘ && v.length === 6;
},
message: ‘qq号必须以1开头且长度是6‘
}
}