插入：

const mysql = require('mysql')

const con = mysql.createConnection({
    host:'localhost',
    user:'root',
    password:'root',
    port:3306,
    database:'myblog'
})

con.connect()

let sql = `insert into blogs (title,content,createtime,author) values ('title1','content1',1607219354313,'dean');`
con.query(sql,(err,data)=>{
    if(err){
        console.error(err)
    }
    console.log(data)
})

查询：

let sql = `select * from blogs;`

修改：

let sql = `update blogs set title='my title1' where author='dean'`

删除

let sql = `delete from blogs where title='my title1'`

只有update操作返回的结果里changedRows:1