sql语句
插入
insert into 表名(字段名1,字段名2) values(值1,值2);
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删除
修改
update 表名 set 字段名1=新值1,字段名2=新值2 where 条件;
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查询
select * from 表名 [where 条件];
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nodejs对数据库的操作
模块 mysql
安装模块
npm i mysql
导入模块
var mysql = require('mysql');
创建链接
var connection = mysql.createConnection({ host user password database});
- host 数据库服务器地址
- user 数据库用户名
- password 数据库密码
- database 数据库名
打开数据库
connection.connect();
执行sql语句
关闭数据库
connection.end();
查操作
你想操作的数据 只需要更改 connection.query()
里面的sql语句即可
var mysql = require('mysql');
var connection = mysql.createConnection({ host : '47.93.184.100', user : 'joe127', password : 'joe127', database : 'joe127' });
connection.connect();
connection.query('SELECT*from user', (error, results, fields)=> { console.log(error) console.log(results) console.log(results[1].username) console.log(fields) });
connection.end();
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增操作
- results 返回的是一个对象
- results.affectedRows 受影响的行数 大于0则成功
- results.insertId 插入这条数据的id
var mysql = require('mysql');
var connection = mysql.createConnection({ host : '47.93.184.100', user : 'joe127', password : 'joe127', database : 'joe127' });
connection.connect();
let id = 4 let name1 = "马化腾" let miao = "真正的大佬"
connection.query(`insert into user(ID,username,des) values('${id}','${name1}','${miao}')`, (error, results, fields)=> { console.log(results) console.log(results.affectedRows) console.log(results.insertId) });
connection.end();
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该操作
var mysql = require('mysql');
var connection = mysql.createConnection({ host : '47.93.184.100', user : 'joe127', password : 'joe127', database : 'joe127' });
connection.connect();
connection.query(`update user set username='马云' where ID = 2;`, (error, results, fields)=> { console.log(results)
});
connection.end();
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删操作
var mysql = require('mysql');
var connection = mysql.createConnection({ host : '47.93.184.100', user : 'joe127', password : 'joe127', database : 'joe127' });
connection.connect();
connection.query(`delete from user where ID = 0;`, (error, results, fields)=> { console.log(results)
});
connection.end();
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