Unable to cast object of type 'Newtonsoft.Json.Linq.JObject' to type 'System.Collections.Generic.Dictionary`2[System.String,System.Object]'

Question

I am trying to insert List of object into table using SqlBulkCopy . When the code hit the line

 var columnNames = ((Dictionary<string, object>)bData[0]).Select(x => x.Key).ToList();'

I got:

'Unable to cast object of type 'Newtonsoft.Json.Linq.JObject' to type 'System.Collections.Generic.Dictionary`2[System.String,System.Object]'' error.

Could you help me?

public Int64 PostBulkMessage(List<object> bData)
{
    DataTable dt = new DataTable();

    var columnNames = ((Dictionary<string, object>)bData[0]).Select(x => x.Key).ToList();

    for (int i = 0; i < columnNames.Count(); i++)
    {
        dt.Columns.Add(columnNames[i]);
    }
    foreach (Dictionary<string, object> customer in bData)
    {
        DataRow dr = dt.NewRow();
        for (int i = 0; i < columnNames.Count(); i++)
        {
            dr[columnNames[i]] = customer[columnNames[i]];
        }
        dt.Rows.Add(dr);
    }
    if (dt.Rows.Count > 0)
    {
        string consString = ConfigurationManager.ConnectionStrings["ConnEntities"].ConnectionString;
        using (SqlConnection con = new SqlConnection(consString))
        {
            using (SqlBulkCopy sqlBulkCopy = new SqlBulkCopy(con))
            {
                //Set the database table name.
                sqlBulkCopy.DestinationTableName = "dbo.BulkSent";
                con.Open();
                sqlBulkCopy.WriteToServer(dt);
                con.Close();
            }
        }
    }

    return 0;
}

Answer 1

Many thanks Stefan and Rahul Sharma for your support. As advised by Stefan i created class and changed the code. Now the bulk insert is working fine. Please verify the below code.

public Int64 PostBulkMessage(List<Bulk> bData)
        {

            DataTable dt = new DataTable();
            dt.Columns.Add("Id", typeof(string));
            dt.Columns.Add("Mobile", typeof(string));
            dt.Columns.Add("MessageContent", typeof(string));

            for (int i = 0; i < bData.Count(); i++)
            {
                DataRow dr = dt.NewRow();
                dr[0] = bData[i].Id;
                dr[1] = bData[i].Mobile;
                dr[2] = bData[i].MessageContent;

                dt.Rows.Add(dr);
            }

            if (dt.Rows.Count > 0)
            {
                string connectionString = ConfigurationManager.ConnectionStrings["ConnEntities"].ConnectionString;
                if (connectionString.ToLower().StartsWith("metadata="))
                {
                    System.Data.Entity.Core.EntityClient.EntityConnectionStringBuilder efBuilder = new System.Data.Entity.Core.EntityClient.EntityConnectionStringBuilder(connectionString);
                    connectionString = efBuilder.ProviderConnectionString;
                }
                using (SqlConnection con = new SqlConnection(connectionString))
                {
                    using (SqlBulkCopy sqlBulkCopy = new SqlBulkCopy(con))
                    {
                        sqlBulkCopy.DestinationTableName = "dbo.BulkMsg";
                        con.Open();
                        sqlBulkCopy.WriteToServer(dt);
                        con.Close();
                    }
                }
            }
            return 0;
        }


 public class Bulk
        {

            public string Id { get; set; }
            public string Mobile { get; set; }
            public string MessageContent { get; set; }
        }