背景，需要在当前上下文中连接两个数据库，且两个数据库都需要使用不同的域账号登录。

首先注意到SqlConnection 对象有个重载的方法，但看了描述貌似不支持 Windows 集成身份验证。

 经测试，确实不支持

那么尝试另外的方法，尝试用C#代码使用另外的用户登录，然后使用新用户的上下文执行一些操作，完整代码如下，需要使用管理员账号执行。当然，该操作不仅限于连接数据库

using Microsoft.Win32.SafeHandles;
using System;
using System.Data.SqlClient;
using System.Runtime.InteropServices;
using System.Security.Principal;
namespace ConsoleApp2
{
    class Program
    {
        [DllImport("advapi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
        public static extern bool LogonUser(String lpszUsername, String lpszDomain, String lpszPassword,
            int dwLogonType, int dwLogonProvider, out SafeAccessTokenHandle phToken);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        public extern static bool CloseHandle(IntPtr handle);

        static void Main(string[] args)
        {
            //var conn = new SqlConnection();

            var userName = "xxxx";
            var password = "xxxxx";
            var domainName = "xxxxx";

            const int LOGON32_PROVIDER_DEFAULT = 0;
            //This parameter causes LogonUser to create a primary token.   
            const int LOGON32_LOGON_INTERACTIVE = 2;

            SafeAccessTokenHandle safeAccessTokenHandle;
            bool returnValue = LogonUser(userName, domainName, password,
                LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT,
                out safeAccessTokenHandle);
            Console.WriteLine("模拟前：");
            Console.WriteLine("Current User:" + WindowsIdentity.GetCurrent().Name);
            WindowsIdentity.RunImpersonated(safeAccessTokenHandle,
                () =>
                {
                    Console.WriteLine("模拟中：");

                    Console.WriteLine("Current User:" + WindowsIdentity.GetCurrent().Name);
                    try
                    {
                        var conn = new SqlConnection("Server=h90sv31000211db.zh.if.atcsg.net\\AP_ADW;Database=DataWhs;Trusted_Connection=SSPI;"
                            );
                        conn.Open();

                        var cmd = new SqlCommand("select 1", conn);
                        Console.WriteLine(cmd.ExecuteScalar());

                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.ToString());
                    }
                });

            Console.WriteLine("模拟后：");
            Console.WriteLine("Current User:" + WindowsIdentity.GetCurrent().Name);


        }
    }
}