How to return dynamic object from SQL query

Question

I have situation where a storeprocdure return collection, but I do not how the object structure because the query is very dynamic.

One query can return:

Id | Location | MarketSegment | ... n columns

and another can return

Id | Sales Rep | Location | Region | ... n columns

I am simply just return a "object" as you can see in the code below. I know this won't work, but how can I set it up so it does?

using (DbContext db = new Context())
{

    var items = db.Database.SqlQuery<object>(
        "SP @Param1, @Param2",
        new SqlParameter("Param1", ped),
        new SqlParameter("Param2", 25)
    ).ToList();

    return Request.CreateResponse<List<object>>(HttpStatusCode.OK, items);
}

EDIT:

I don't know if showing the SP will help in anyways, except if I can explain it more.

Each columns are represented as Custom Fields. Users are able to create n numbers of Custom Fields. So If you run the SP for User1 and he has 5 custom fields, then each custom fields will be represented in Columns, but If User2 has 3 custom fields, only 3 columns will be represented. What I don't have control over is the Custom Field Name and number of custom fields.

Please show us what SP is.

Dour High Arch
– Dour High Arch

2014-08-25 21:14:05 +00:00
Commented Aug 25, 2014 at 21:14 — Dour High Arch
– Dour High Arch, Commented Aug 25, 2014 at 21:14
please see edited comment.

jmogera
– jmogera

2014-08-25 21:31:08 +00:00
Commented Aug 25, 2014 at 21:31 — jmogera
– jmogera, Commented Aug 25, 2014 at 21:31

Yuliam Chandra · Accepted Answer · 2014-08-26 03:05:33Z

You can't use SqlQuery<T> for custom fields.

Creates a raw SQL query that will return elements of the given generic type. The type can be any type that has properties that match the names of the columns returned from the query, or can be a simple primitive type. - MSDN

But, you can use ExecuteReader to achieve that.

using (var db = new Context())
{
    db.Database.Connection.Open();

    var cmd = db.Database.Connection.CreateCommand();
    cmd.CommandText = "SP @Param1, @Param2";
    cmd.Parameters.Add(new SqlParameter("Param1", ped));
    cmd.Parameters.Add(new SqlParameter("Param2", 25));

    List<List<object>> items = new List<List<object>>();
    var reader = cmd.ExecuteReader();
    while (reader.Read())
    {
        var item = new List<Object>();
        items.Add(item);

        for (int i = 0; i < reader.FieldCount ; i++)
            item.Add(reader[i]);
    }

    return Request.CreateResponse<List<object>>(HttpStatusCode.OK, items);
}

LMK · Accepted Answer · 2019-09-08 21:35:24Z

10

If on SQL 2016 or newer, add "FOR JSON AUTO" to your query to return as JSON, e.g:

var json = db.Database.SqlQuery<string>("Select x, y, z FROM tbl FOR JSON AUTO").First();

Then use Json.Net to create a dynamic object using

var myDynamic = JObject.Parse(json)

answered Sep 8, 2019 at 21:35

LMK

1,5811 gold badge14 silver badges16 bronze badges

1 Comment

Nahid Over a year ago

It might give error in ef core 8. Use the below one db.Database.SqlQuery<string>("Select x, y, z FROM tbl FOR JSON AUTO").ToList().First();

Onosa · Accepted Answer · 2014-08-25 21:17:43Z

-3

If you know what all the possible columns could be returned, there is no issue with using a class that has more properties than you need.

public class Data
{
public int ID {get;set;}
public string SalesRep {get;set;}//Simply will be empty in the first example, but populated in the second.
public string Location {get;set;}
}

answered Aug 25, 2014 at 21:17

Onosa

1,2731 gold badge12 silver badges28 bronze badges

1 Comment

statler Over a year ago

Sadly, this is not true (bitter voice of experience). Doing this will result in Exception thrown: 'System.IndexOutOfRangeException' in System.Data.dll If you catch the error and continue, then it will still work, but performance becomes horrible. I have a case where it increases execution from 290 ms to 4 seconds.

Collectives™ on Stack Overflow

How to return dynamic object from SQL query

3 Answers 3

Comments

1 Comment

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related