Question

In Users model, I have DateTime dtContractStart and DateTime dtContractEnd.

In UserModel model, I have String dtContractStart and String dtContractEnd.

To can perform a string cast with Linq query, I want to try something like that :

DateTime start;
DateTime end;

var users = DB.Users
    .Select(user => new UserModel
    {
        id = user.id,
        firstname = user.firstname,
        lastname = user.lastname,
        dtContractStart = "",
        dtContractEnd = "",
    }
        && start = user.dtContractStart
        && end = user.dtContractEnd
    )
    .ToList();

users.ForEach(user =>
    user.dtContractStart = start.toString() &&
    user.dtContractEnd = end.toString()
);

Is it possible? I don’t find the good syntax.

Answer 1

If the Linq provider you’re using doesn’t accept the call to ToString, you can execute your query in two steps, using AsEnumerable to force the query execution:

var users = DB.Users
    .Where(...) // Whatever filtering clause inside your query
    .AsEnumerable() // Force the query execution, switching to Linq to Objects
    .Select(user => new UserModel
    {
        id = user.id,
        firstname = user.firstname,
        lastname = user.lastname,
        dtContractStart = user.dtContractStart.ToString(),
        dtContractEnd = user.dtContractEnd.ToString(),
    })
    .ToList();