尝试从 nodejs 创建 SQL 数据库连接时出现连接错误

Connection Error while trying to create SQL DB connection from nodejs

尝试从 NodeJs class 连接 SQL 数据库时,出现错误:

ConnectionError: Connection not yet open

var sql = require("mssql");
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyParser.json());
var executeQuery = function(res, query) { 

var conn = new sql.ConnectionPool(dbConfig);

conn.connect()
     .then(function (pool) {

         // create Request object
         var request = new sql.Request(pool);                          
         // query to the database
         request.query(query, function (err, queryResult) {
             if (err) {
                 console.log(err);
                 res.send(err);
             } else {
                 res.send(queryResult);
             }
         });
         conn.close();
    });           
}

您将在处理 request.query 之前关闭连接,因为这是一个异步调用。在 request.query.

的回调中移动 conn.close()
var conn = new sql.ConnectionPool(dbConfig);

conn.connect()
     .then(function (pool) {

         // create Request object
         var request = new sql.Request(pool);                          
         // query to the database
         request.query(query, function (err, queryResult) {
             if (err) {
                 console.log(err);
                 res.send(err);
             } else {
                 res.send(queryResult);
             }
             conn.close();
         });
    });           
}