597 node之mysql2

认识mysql2

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使用mysql2

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Prepared Statement（预编译语句）

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Connection Pools

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Promise方式

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01_mysql2的基本使用.js

const mysql = require('mysql2');

// 1.创建数据库连接
const connection = mysql.createConnection({
  host: 'localhost',
  port: 3306,
  database: 'coderhub',
  user: 'root',
  password: 'Coderwhy888.'
});

// 2.执行SQL语句
const statement = `
  SELECT * FROM products WHERE price > 6000;
`
connection.query(statement, (err, results, fields) => {
  console.log(results);
});

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02_预处理语句.js

const mysql = require('mysql2');

// 1.创建数据库连接
const connection = mysql.createConnection({
  host: 'localhost',
  port: 3306,
  database: 'coderhub',
  user: 'root',
  password: 'Coderwhy888.'
});

// 2.执行SQL语句
// 在真正执行时会给?提供实际的参数才会执行
const statement = `
  SELECT * FROM products WHERE price > ? AND score > ?;
`
connection.execute(statement, [6000, 7], (err, results) => {
  console.log(results);
});

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03_连接池的使用.js

const mysql = require('mysql2');

// 1.创建连接池
const connections = mysql.createPool({
  host: 'localhost',
  port: 3306,
  database: 'coderhub',
  user: 'root',
  password: 'Coderwhy888.',
  connectionLimit: 10
});

// 2.使用连接池
const statement = `
  SELECT * FROM products WHERE price > ? AND score > ?;
`
connections.execute(statement, [6000, 7], (err, results) => {
  console.log(results);
});

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04_promise的方式.js

const mysql = require('mysql2');

// 1.创建连接池
const connections = mysql.createPool({
  host: 'localhost',
  port: 3306,
  database: 'coderhub',
  user: 'root',
  password: 'Coderwhy888.',
  connectionLimit: 10
});

// 2.使用连接池
const statement = `
  SELECT * FROM products WHERE price > ? AND score > ?;
`
connections.promise().execute(statement, [6000, 7]).then(([results]) => {
  console.log(results);
}).catch(err => {
  console.log(err);
});

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