Microsoft SQL Server, 错误：4064的解决方法

关注

原创最新推荐文章于 2026-04-23 15:56:16 发布 2.1w 阅读 AI 写同款· GEO 优化 ›

SQL Server错误代码解析与故障排除指南关系型数据库管理系统(RDBMS)通过错误代码机制实现系统与用户的精确通信。SQL Server作为主流企业级数据库，其错误代码体系包含错误编号、严重级别和状态代码等结构化信息，为DBA和开发人员提供快速故障定位能力。从技术原理看，错误代码本质上是数据库引擎的状态反馈机制，通过预定义的代码体系实现标准化的错误报告。在工程实践中，掌握错误代码解析能显著提升数据库运维效率，特别是在身份验证(如错误18456)、连接问题(如错误233)和资源管理(如错误701)等典型场景。通过结合SQL Server错误日志和扩阅读详情

SQL SERVER – Fix : Error: 4064 – Cannot open user default database. Login failed. Login failed for user

November 4, 2008 by pinaldave

I have received following question nearly 10 times in last week though emails. Many users have received following error while connecting to the database. This error happens when database is dropped for which is default for some of the database user. When user try to login and their default database is dropped following error shows up.

Cannot open user default database. Login failed.
Login failed for user ‘UserName’. (Microsoft SQL Server, Error: 4064)

The fix for this problem is very simple.

Fix/Workaround/Solution:

First click on Option>> Button of “Connect to Server” Prompt.

Now change the connect to database to any existing database on your server like master or msdb.

Now click on connect and it will successfully log you in. Once you login in the system run following statement for your username and it should fix your problem. Make sure to replace [test] with your username and master with yourdatabase name.

ALTER LOGIN [test] WITH DEFAULT_DATABASE = master
GO