ConnectionError:无法连接到 localhost:15000 毫秒内未定义

I am using KnexJs attempting to connect to a local Microsoft SQL Server Express. However, with the below configuration, I am getting an error. I've followed the typical steps, but I'm still getting the error.

我尝试过的:

1. 为数据库设置 SQL Server 身份验证登录
2. 在服务器上启用 SQL Server 身份验证
3. 在服务器上启用 TCP/IP
4. 重启 Windows 服务
5. 通过 SQL Server Management Studio 重启 SQL Server
6. 验证通过 SQL Server Management Studio 登录的能力

配置/查询代码:

    let mssql = knex({
        client: 'mssql',
        connection: {
          host: 'localhost\sqlexpress',
          user: 'test',
          password: 'test',
          database: 'AdventureWorks2017',
          // port:1433,
          // options: {
          //   trustedConnection: true
          // },
          useNullAsDefault: true
        }
      });

    mssql.raw('select 1 as result').then(function (result) {
      console.log('result');
      console.log(result);
      mainWindow.webContents.send('testConnectionResponse', result === 1);
      event.sender.send('testConnectionResponse', result === 1);
    }).catch(function (err) {
      console.log(err);
      mainWindow.webContents.send('query-error', err);
    }).finally(() => {
      mssql.destroy();
    });

错误:

ConnectionError: 无法连接到 localhost:undefined in 15000ms