Net core dapper and postgres jsonb column

Question

I want to POST some custom JSON to my postgres jsonb column via postman using the below request.

The custom part is sent in the "Settings" > "data" node. I don't want to apply the custom part to a model I just want to send in any kind of json and store it.

{
    "name": "Test",
    "settings": {
        "data": {
            "customdata": "hello",
            "custommore": "bye"
        }
    }
}

The "data" node is modelled - like this:

public string Data { get; set; } //I have tried JSONDocument and Jsonb types to no avail.

Postman errors with this:

"errors": {
        "$.settings.data": [
            "The JSON value could not be converted to System.String. Path: $.settings.data | LineNumber: 3 | BytePositionInLine: 17."
        ]
}

The request doesn't even hit my controller method. I think it is because the customdata and custommore is not mapped to a model.

Is there a way of sending in custom JSON data that is not fixed to a model of any kind - or must it be part of a model?

I'm struggling to find anything about this that doesn't relate to EF core which is not what I am using.

Answer 1

You can use custom model binding,and get json data from HttpContext.Request.Body,and then use sonConvert.DeserializeObject to get json object.You can set the data to the format you want.

Here is a demo:

DataBinder:

public class DataBinder:IModelBinder
    {
        public Task BindModelAsync(ModelBindingContext bindingContext)
        {
            if (bindingContext == null)
            {
                throw new ArgumentNullException(nameof(bindingContext));
            }
            var model1 = new Customer();



            using (var reader = new StreamReader(bindingContext.HttpContext.Request.Body))
            {
                var body = reader.ReadToEndAsync();

                var mydata = JsonConvert.DeserializeObject<JObject>(body.Result);



                model1.Name = mydata["name"].ToString();
                model1.Settings = new Settings
                {
                    Data = mydata["settings"]["data"].ToString()
                };

            }

            bindingContext.Result = ModelBindingResult.Success(model1);
            return Task.CompletedTask;
        }
    }

Controller:

public IActionResult TestCustomModelBinding([ModelBinder(BinderType = typeof(DataBinder))]Customer customer) {
            return Ok();
        }

result: