ModelState.IsValid is false on datetime post with EF Database First

Question

I am using Microsoft's Entity Framework 6.1.3. with Database First (from an Azure SQL Server instance). The automatically generated Entity looks like this - the database column is datetime2(0) but really I just want to persist the date but that's another discussion:

public partial class Liquidated
{
    public long ID { get; set; }
    public System.DateTime LiquidationDate { get; set; }
    public string Comment { get; set; }
}

The auto-generated Controller:

    // POST: api/Liquidations
    [ResponseType(typeof(Liquidated))]
    public IHttpActionResult PostLiquidated(Liquidated liquidated)
    {

        if (!ModelState.IsValid)
        {
            return BadRequest(ModelState);
        }

The unit test using RestSharp:

        var client = new RestClient("http://localhost:64185/api/Liquidations");
        var request = new RestRequest(Method.POST);

        request.AddHeader("cache-control", "no-cache");
        request.AddHeader("authorization", "bearer " + token.access_token);
        request.AddHeader("content-type", "application/x-www-form-urlencoded");
        request.AddHeader("audience", "Any");
        request.AddHeader("accept-language", "en-gb");
        request.AddHeader("accept", "application/json");

        var liquidation = new Liquidated();

        liquidation.LiquidationDate = DateTime.Now;
        liquidation.Comments = "Updated group name 1";

        request.AddObject(liquidation);

        IRestResponse<Liquidated> response = client.Execute<Liquidated>(request);

But when I inspect the ModelState in the Controller it is not valid and shows the following format error for LiquidationDate:

"The value '18/04/2017 14:26:12' is not valid for LiquidationDate."

I've searched many posts, tried to force the formatting (is it a question of date formatting between C# entities and SQL Server?) but I can't see what I'm doing wrong. Any help is much appreciated!

The model state error is because you are posting the wrong data to the API, it's nothing to do with Entity Framework. I would guess it's most likely something to do with date format (`dd/mm/yyy` vs `mm/dd/yyyy` for example) — DavidG, Apr 18 '17 at 14:19
It is recommended using DateTimeOffset with EF. http://stackoverflow.com/questions/9389954/entity-framework-mapping-datetimeoffset-to-sql-server-datetime — Steve McCormack, Apr 18 '17 at 14:22
@DavidG - thanks for the comment. I removed any date data from the unit test post and that worked. I then replaced the datetime in the client-side class and changed it to a string, of which I have complete formatting control i.e. yyyy-MM-dd. I think I was putting too much faith into RestSharp's ability to format appropriately - not sure it is even possible but will find out. — Bexbissell, Apr 18 '17 at 14:45

score 0 · Answer 1 · edited May 23 '17 at 12:17

If posting JSON data to Web API, make sure that date values are sent in ISO 8601 format (2017-04-18T14:22:59Z). Else you run into problems with the modelbinder.

Example of JS function to convert UTC Javascript date object to ISO 8601 string (date only without time):

/// <summary>
/// Takes a utc js date and converts it to a iso8601 utc string
/// </summary>
GlobalJsHelpers.Iso8601FromUtc = function(utcDate) {
    //create a two digit month string (01-12)
    var month = ('0' + (utcDate.getUTCMonth() + 1)).substr(-2);
    //create a two digit day string (01-31)
    var day = ('0' + utcDate.getUTCDate()).substr(-2);
    return utcDate.getUTCFullYear() + '-' + month + '-' + day;
};

See Why is RestSharp deserializing two dates differently? on how to trick RestSharp.

score 0 · Accepted Answer · answered Apr 18 '17 at 15:22

Following on from @DavidG's comment I changed the client-side Liquidated class to contain a string instead of datetime:

public partial class Liquidated
{
    public long ID { get; set; }
    public string LiquidationDate { get; set; }
    public string Comments { get; set; }
}

and then did the formatting outside of RestSharp:

        var client = new RestClient("http://localhost:64185/api/Liquidations");
        var request = new RestRequest(Method.POST);
        request.AddHeader("postman-token", "a95ce9b5-8c7f-e223-faa6-3768f7edd10c");
        request.AddHeader("cache-control", "no-cache");
        request.AddHeader("authorization", "bearer " + token.access_token);
        request.AddHeader("content-type", "application/x-www-form-urlencoded");
        request.AddHeader("audience", "Any");
        request.AddHeader("accept-language", "en-gb");
        request.AddHeader("accept", "application/json");

        var liquidation = new Liquidated();

        liquidation.LiquidationDate = DateTime.Now.ToString("yyyy-MM-dd");
        liquidation.Comments = "Updated group name 1";

        // request.DateFormat = "yyyy-MM-dd"; // This is ignored by RestSharp
        request.AddObject(liquidation);

        IRestResponse<Liquidated> response = client.Execute<Liquidated>(request);

Having read the RestSharp GitHub issue log: https://github.com/restsharp/RestSharp/issues/629, there are no plans to support this facility.

Thanks for pointing me in the right direction.

ModelState.IsValid is false on datetime post with EF Database First

2 Answers2