设置和调用如何在web.config中的全球连接

在web.config

<connectionStrings>

  <add name="Connection" connectionString="Data Source=ESS-8\\SQLEXPRESS;Initial Catalog=Inventory1;Integrated Security=True;" providerName="System.Data.SqlClient"/>

</connectionStrings>

'string' does not contain a definition for 'Open' and no extension method 'Open' accepting a first argument of type 'string' could be found (are you missing a using directive or an assembly reference?)