The Include path expression must refer to a navigation property defined on the type.in eager loading

I try to include anonymous type like this :
I want all incomelist attributes in addition to CompanyTitle ,PeriodTypeName )

 var incomeList = ctx.IncomeLists.Include(i => new
                {
                    CompanyTitle = i.CompanyId.ToString() + "/" + i.Company.CompanyName,
                    PeriodTypeName = i.ListPeriods.Select(lp => lp.PeriodType.PeriodTypeName)
                }).ToList()

My model section like this :

but i get the following exception :

The Include path expression must refer to a navigation property
defined on the type. Use dotted paths for reference navigation
properties and the Select operator for collection navigation
properties. Parameter name: path

The result should be the datasource to Gridview.

Answers:

Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

You cannot use Include to select data like this. Include is used to load related data. You should load your entities using Include then select what you want. Remember to remove .ToString() from CompanyId. EF will do it for you. Your query should look like this:

var incomeList = ctx.IncomeLists
    .Include(i => i.Company)
    .Include(i => i.ListPeriods.Select(lp => lp.PeriodType))
    .Select(i => new 
    {
        CompanyTitle =  i.CompanyId + "/" + i.Company.CompanyName,
        PeriodTypeNames = i.ListPeriods.Select(lp => lp.PeriodType.PeriodTypeName)
    })
    .ToList();

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0