当我尝试连接SQL Server时，我得到以下错误:
在建立与SQL Server的连接时，发生了与网络相关或特定于实例的错误。未找到服务器或无法访问服务器。验证实例名称是否正确，SQL Server是否配置为允许远程连接。(提供商:Named Pipes提供商，错误:40 -无法打开到SQL Server的连接)
当我试图在Visual Studio 2010中将数据库配置为gridview时抛出此错误。我不知道如何调试这个错误。
如何调试此错误?除了错误消息中提到的步骤之外，我还应该采取哪些步骤来确定这里到底发生了什么?
当前回答
除了尝试Teo Chuen Wei Bryan建议的所有方法外，还要确保在连接字符串中引用了正确的服务器/实例名称。
如果您在数据库服务器或web上使用主机名/实例的简写形式。配置文件，确保您使用完全限定域名(FQDN)/实例
此外，要从不存在SQL server客户端的服务器测试连通性，
——>创建一个文本文件，并将其扩展名为。udl
右键单击文件，你可以看到连接选项卡。
——>输入服务器名和登录信息，测试连接到数据库服务器。
希望这能有所帮助。
其他回答
我几乎什么都试过了。然后，我已经卸载了Malwarebytes。一种声称可以删除恶意软件的软件(通常可以)。在那之后，一切都好了。也许有人会因为同样的原因遇到同样的问题。
I got this error after working at distance (VPN) for a few years. At some point in time I must have changed my DNS settings to the IP address of my home router. Now I was (again) in the same network as the server, and got the error above. the solution was to open "Network status" / "Change adapter options" and right click the active internet connection (Ethernet in my case) to get to the properties of IPv4. Under "Use the following DNS server addresses" I entered the local IP address of my server, and what do you know...! The computer contacted the domain (on the server) and SQL Server opened up.
要检查是否有相同的问题，打开cmd并输入 夜间电报/ dsgetdc:域名 [用域名交换"domainname"] 如果您得到一条消息说“获取DC名称失败:Status = 1355 0x54b ERROR_NO_SUCH_DOMAIN”，您可能是域名错误，或者您可能有这个问题。
似乎您的localdb实例没有运行。 要在计算机启动时启动它，添加到您的开始菜单\启动文件夹BAT文件与以下行
sqllocaldb start name_of_instance
其中name_of_instance是要启动的localdb实例的名称。 您可以使用sqllocaldb i在命令行中列出可用的实例。
例如，如果您正在使用SQL Server Management Studio并连接到服务器名称(localdb)\v11.0，那么您的BAT文件将如下所示
sqllocaldb start v11.0
I had the same issue after upgrading my Windows to Windows Pro 10 21H2. I have two SQL instances - 2014 and 2019 and I was not able to connect only to 2019 one. I restarted the computer, restarted all SQL related services. Two of the services were showing errors (SQL Server and SQL Server agent) and I was not able to start them. I could not also start these two services from C:\Windows\SysWOW64\SQLServerManager15.msc In the logs (C:\Program Files\Microsoft SQL Server\MSSQL15.MSSQLSERVER01\MSSQL\Log) I saw these lines:
Initializing the FallBack certificate failed with error code: 15, state: 29, error number: 0.
Error: 17190, Severity: 16, State: 1.
Unable to initialize SSL encryption because a valid certificate could not be found, and it is not possible to create a self-signed certificate.
Error: 17182, Severity: 16, State: 1.
TDSSNIClient initialization failed with error 0x80092004, status code 0x80. Reason: Unable to initialize SSL support. Cannot find object or property.
Error: 17182, Severity: 16, State: 1.
TDSSNIClient initialization failed with error 0x80092004, status code 0x1. Reason: Initialization failed with an infrastructure error. Check for previous errors. Cannot find object or property.
Error: 17826, Severity: 18, State: 3.
Could not start the network library because of an internal error in the network library. To determine the cause, review the errors immediately preceding this one in the error log.
Error: 17120, Severity: 16, State: 1.
SQL Server could not spawn FRunCommunicationsManager thread. Check the SQL Server error log and the operating system error log for information about possible related problems.
原来在升级后，服务的“Log On”属性(服务属性上的第二个选项卡)被设置为NT AUTHORITY\NETWORK SERVICES。当我将其更改为“本地系统帐户”时，我能够启动服务并连接到MS SQL 2019实例。
这个msdn论坛的帖子帮助我找到了这个。
我必须运行SQL Server浏览器服务到SQL Server配置管理器。 如果没有这个，安装就不能发现新创建的服务。
