express框架链接池的使用

引入mysql模块 设置全局pool

let mysql = require('mysql');
let pool = global.pool;

创建链接池

if (!pool) {
  //创建连接池
  pool = mysql.createPool({
    // host: '101.132.47.132',
    host: '101.132.47.132',
    database: 'Bibased',
    user: 'root',
    password: 'root'
  });
  //将连接挂载到global
  global.pool = pool;
}

获取连接池链接

//获取链接
function getConnection() {
  return new Promise(function (resolve, reject) {
    pool.getConnection(function (err, conn) {
      if (!err) {
        resolve(conn);
      } else { 
        reject(err);
      }
    });
  })
}

执行数据库操作sql返回sql数据

//执行sql
function execute(sql) {
  return new Promise(function (resolve, reject) {
    var connection; 
    getConnection().then(function (conn) {
      connection = conn;
      conn.query(sql, function (err, result) {
        if (!err) {
          resolve(result)
        } else {
          reject(err)
        }
      });
    }).catch(function (err) {
      reject(err)
    }).finally(function () {
      if (connection) {
        connection.release();
      }
    });
  });
}

返回当前模块数据

module.exports = {
  getConnection,
  execute
};