Chr*_*eek 25 sql-server node.js express node-mssql
我想在Node JS Express 4 Web应用程序中使用node-mssql作为MSSQL数据库连接器.路径处理程序逻辑在单独的文件中处理.
如何创建单个/全局连接池并在处理路由逻辑的多个文件中使用它？我不想在每个路由处理函数/文件中创建一个新的连接池.
Chr*_*eek 50
我提问并回答了这个问题已经3年了.从那时起,一些事情发生了变化.这是我今天建议的基于ES6,mssql 4和Express 4的新解决方案.它尚未经过测试.
这里有两个关键要素.
在 server.js
const express = require('express')
// require route handlers.
// they will all include the same connection pool
const set1Router = require('./routes/set1')
const set2Router = require('./routes/set2')
// generic express stuff
const app = express()
// ...
app.use('/set1', set1Router)
app.use('/set2', set2Router)
// No need to connect the pool
// Just start the web server
const server = app.listen(process.env.PORT || 3000, () => {
const host = server.address().address
const port = server.address().port
console.log(`Example app listening at http://${host}:${port}`)
})
在 db.js
const sql = require('mssql')
const config = {/*...*/}
const poolPromise = new sql.ConnectionPool(config)
.connect()
.then(pool => {
console.log('Connected to MSSQL')
return pool
})
.catch(err => console.log('Database Connection Failed! Bad Config: ', err))
module.exports = {
sql, poolPromise
}
在routes/set1.js和routes/set2.js
const express = require('express')
const router = express.Router()
const { poolPromise } = require('./db')
router.get('/', async (req, res) => {
try {
const pool = await poolPromise
const result = await pool.request()
.input('input_parameter', sql.Int, req.query.input_parameter)
.query('select * from mytable where id = @input_parameter')
res.json(result.recordset)
} catch (err) {
res.status(500)
res.send(err.message)
}
})
module.exports = router
总结一下
由于模块缓存,您将始终获得相同的承诺,并且该承诺将一次又一次地使用它首次解析的池解析.因此,每个路由器文件使用相同的池.
顺便说一下:在快速路线上有更简单的方法来尝试捕获,我将不会在这个答案中介绍.在这里阅读:https://medium.com/@Abazhenov/using-async-await-in-express-with-node-8-b8af872c0016
旧的解决方案
这是我3年前发布的解决方案,因为我相信我有一个值得分享的答案,我无法在其他地方找到有记录的解决方案.同样在node-mssql 的一些问题(#118,#164,#165)中讨论了这个主题.
在 server.js
var express = require('express');
var sql = require('mssql');
var config = {/*...*/};
//instantiate a connection pool
var cp = new sql.Connection(config); //cp = connection pool
//require route handlers and use the same connection pool everywhere
var set1 = require('./routes/set1')(cp);
var set2 = require('./routes/set2')(cp);
//generic express stuff
var app = express();
//...
app.get('/path1', set1.get);
app.get('/path2', set2.get);
//connect the pool and start the web server when done
cp.connect().then(function() {
console.log('Connection pool open for duty');
var server = app.listen(3000, function () {
var host = server.address().address;
var port = server.address().port;
console.log('Example app listening at http://%s:%s', host, port);
});
}).catch(function(err) {
console.error('Error creating connection pool', err);
});
在 routes/set1.js
var sql = require('mssql');
module.exports = function(cp) {
var me = {
get: function(req, res, next) {
var request = new sql.Request(cp);
request.query('select * from test', function(err, recordset) {
if (err) {
console.error(err);
res.status(500).send(err.message);
return;
}
res.status(200).json(recordset);
});
}
};
return me;
};
配置应用程序时(如创建快速服务器时),建立数据库连接.确保在您需要所有路线之前完成此操作!(finagle文件顶部的要求)
就像文档一样:
var sql = require('mssql');
var connection = new sql.Connection(.....
//store the connection
sql.globalConnection = connection;
然后在所有路径文件中,您可以执行以下操作:
var sql = require('mssql');
var sqlConn = sql.globalConnection;
var request = new sql.Request(sqlConn);
//...
应该这样做!
总而言之,使用knex来管理你的MySQL查询构建.它有一个内置的连接池,您以相同的方式存储连接的knex实例.以及慷慨的帮助.
src/config.jsexport default {
database: {
server: process.env.DATABASE_SERVER || '<server>.database.windows.net',
port: 1433,
user: process.env.DATABASE_USER || '<user>@<server>',
password: process.env.DATABASE_PASSWORD || '<password>',
database: process.env.DATABASE_NAME || '<database>',
connectionTimeout: 30000,
driver: 'tedious',
stream: false,
options: {
appName: '<app-name>',
encrypt: true
}
}
};
src/server.jsimport sql from 'mssql';
import express from 'express';
import config from './config';
// Create and configure an HTTP server
const server = express();
server.set('port', (process.env.PORT || 5000));
// Register Express routes / middleware
server.use('/api/user', require('./api/user');
// Open a SQL Database connection and put it into the global
// connection pool, then launch the HTTP server
sql.connect(config.database, err => {
if (err) {
console.log('Failed to open a SQL Database connection.', err.stack);
}
server.listen(server.get('port'), () => {
console.log('Node app is running at http://127.0.0.1:' + server.get('port'));
});
});
sql.on('error', err => console.log(err.stack));
src/api/user.jsimport sql from 'mssql';
import { Router } from 'express';
const router = new Router();
router.get('/:id', async (req, res, next) => {
try {
const request = new sql.Request();
request.input('UserID', req.params.id);
request.multiple = true;
const dataset = await request.query(`
SELECT UserID, Name, Email
FROM [User] WHERE UserID = @UserID;
SELECT r.RoleName FROM UserRole AS r
INNER JOIN [User] AS u ON u.UserID = r.UserID
WHERE u.UserID = @UserID
`);
const user = dataset[0].map(row => ({
id: row.UserID,
name: row.Name,
email: row.Email,
roles: dataset[1].map(role => role.RoleName)
})).shift();
if (user) {
res.send(user);
} else {
res.statusCode(404);
}
} catch (err) {
next(err);
}
});
export default router;
另请参阅 MSSQL SDK for Node.js,T-SQL Reference,React Starter Kit
这就是我的做法，我认为它比其他一些解决方案要简单一些。
数据库文件（db.js）：
const sql = require('mssql')
const config = {}
const pool = new sql.ConnectionPool(config)
.connect()
.then(pool => {
console.log('Connected to MSSQL')
return pool
})
.catch(err => console.log('Database Connection Failed! Bad Config: ', err))
module.exports = {
sql, pool
}
询问：
const { pool, sql } = require('../db')
return pool.then(conn => {
const ps = new sql.PreparedStatement(conn)
ps.input('xxxx', sql.VarChar)
return ps.prepare(`SELECT * from table where xxxx = @xxxx`)
.then(data => ps.execute({ xxxx: 'xxxx' }))
})
编辑：更新以匹配 Christiaan Westerbeek 的主旨，该主旨更加清晰。
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