WebApi OData 4 , second POST endpoint for bulk insertion in the controller

Question

I have a basic WebApi OData 4 controller for TEAM model which has a POST action for adding a new TEAM to the database.

    public async Task<IHttpActionResult> Post(USER_TEAMS userTeam)
    {
        if (!ModelState.IsValid)
        {
            return BadRequest(ModelState);
        }
        context.USER_TEAMS.Add(userTeam);
        await context.SaveChangesAsync();
        return Created(userTeam);
    }

I want to have another endpoint in that controller for bulk insertion of teams which takes a list of team objects and adds them to the database. What is the best approach in WebApi OData 4 to do that?

Answer 1

The OData spec includes a batching concept, but for this problem an OData action is a cleaner solution. The action will be bound to the Teams entity set and will accept a collection of Team entities in the request payload. (I've changed USER_TEAMS to Team in the code below.)

Given the following simple definition of Team entity type:

public class Team
{
    public int Id { get; set; }
    public string Name { get; set; }
}

First, define the action method in the same controller as your Post method.

    [HttpPost]
    public IHttpActionResult BulkAdd(ODataActionParameters parameters)
    {
        if (!ModelState.IsValid)
        {
            return BadRequest();
        }

        var newTeams = (IEnumerable<Team>)parameters["NewTeams"];

        // Your data access layer logic goes here.

        return this.StatusCode(HttpStatusCode.NoContent);
    }

Then declare the OData action in your Web API configuration code.

    var builder = new ODataConventionModelBuilder();

    builder.Namespace = "TeamService";
    builder.EntitySet<Team>("Teams");
    builder.EntityType<Team>().Collection
        .Action("BulkAdd")
        .CollectionParameter<Team>("NewTeams");

Note in the above:

• EntityTypeConfiguration<T>.Collection is necessary to bind the action to the Team entity set (vs. a single Team entity)
• ActionConfiguration.CollectionParameter<T> is necessary to specify that the parameter is a collection (vs. a scalar)

On the client, invoke the action as follows.

POST http://domain/Teams/TeamService.BulkAdd
Content-Type: application/json

{"NewTeams": [{"Name": "Demons"}, {"Name": "Angels"}]}