我这是在学习MVC3.0时出现的错误，其实呢这个问题主要是因为web.config配置文件访问数据库的时候连接出错造成的
<connectionStrings>
<add name="ApplicationServices"
connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true"
providerName="System.Data.SqlClient" />
<add name="MovieDBContext" connectionString=" Data Source=.\SQLEXPRESS; Initial Catalog=Movies;Persist Security Info=True; User ID=sa;Password=123456 " providerName="System.Data.SqlClient" />
</connectionStrings>
改为
<connectionStrings>
<add name="ApplicationServices"
connectionString="data source=.;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true"
providerName="System.Data.SqlClient" />
<add name="MovieDBContext" connectionString=" Data Source=.; Initial Catalog=Movies;Persist Security Info=True; User ID=sa;Password=123456 " providerName="System.Data.SqlClient" />
</connectionStrings>
原因：因为你登陆数据库的时候用的服务器名称是"."，所以不能用".\SQLEXPRESS"
)
)
)
