Question: I am learning with this so bear with me...I am trying to create the DB object to access the table.

```
AppDatabaseDataContext appDb = new AppDatabaseDataContext();

```

This gives me an error, so I create the constructor...

```
public AppDatabaseDataContext()
{

} 

```

Now this tells me that `System.Data.Linq.DataContext` does not contain a constructor that takes 0 parameters. Why? 

Thanks!

Answer: 
Sometimes LINQ2SQL might become messy on properties window and the connection string might disapear. 
If you can, restart all over, remove de Dbml and but DON´T FORGET to delete from the web.config the connection string. Add a new Linq2SQL to your project and let the LINQ2SQL to create the connection string for U in the web.config.
```
Just Change your connection string just like  
<connectionStrings>
    <add name="DBLabConnectionString" 
         connectionString="Data Source=.\SQLExpress;Initial Catalog=DatabaseName;
         Integrated Security=True" 
         providerName="System.Data.SqlClient" />
 </connectionStrings>

```