mysql.js
const mysql = require("mysql2");
class MysqlModel {
constructor() {
this.mysqlConfig = config.mysql;
}
/**
* 实例化mysql
*/
mysqlInstance() {
const poolCluster = mysql.createPoolCluster({
removeNodeErrorCount: 1, // Remove the node immediately when connection fails.
defaultSelector: "RR" //RR,RANDOM,ORDER
});
const mysqlNodes = this.mysqlConfig;
for (let node in mysqlNodes) {
poolCluster.add(`${node}`, mysqlNodes[`${node}`]);
}
return new Promise((resolve, reject) => {
poolCluster.getConnection(function (err, connection) {
if (err) {
reject(err);
} else {
resolve([
connection,
poolCluster
]);
}
})
})
}
/**
* 获取mysql数据库连接
*/
async getConnection() {
return await this.mysqlInstance();
}
}
async function mysqlDBUtil() {
try {
const db = new MysqlModel();
const [conn, pool] = await db.getConnection();
log(46, 'mysql连接成功')
/**
* 回滚事务
*/
const rollback = async function () {
conn.rollback();
log('mysql事务发生回滚......rollback')
}
/**
* 数据库操作
* @param {} sql
* @param {*} options
*/
const query = function (sql, options) {
return new Promise((resolve, reject) => {
conn.query(sql, options, function (error, results, fields) {
if (error) {
reject(error);
} else {
resolve(results);
}
})
})
}
/**
*提交事务
*/
const commit = function () {
return new Promise((resolve, reject) => {
conn.commit(function (err) {
if (err) {
reject(err);
}
log('mysql事务提交......commit')
});
})
}
/**
* 关闭连接池，mysql2的包自己不会释放
*/
const close = async function () {
pool.end();
log('mysql连接池关闭.....close');
}
return {
rollback,
commit,
close,
query
}
} catch (error) {
throw new Error(error);
}
}
module.exports = mysqlDBUtil;
//调用
const db = await mysqlUtil();
try {
const sql = ` SELECT * FROM user `;
const result = await db.query(sql);
return result;
}catch (error) {
await db.rollback();
}finally{
awit db.close();
}