"Column 'abc' does not belong to a table.

See more:

C#

SQL

VS2017

My combo box does not load and keeps showing this error

Column 'Item_GenName' does not belong to a table. 

Here's the code:

void loadgeneric()
        {
            string constring = "Data Source=D-HOS-MIS2;Initial Catalog=Consignment_db;Persist Security Info=True;User ID=sa;Password=t.july.01";
            string query = "select distinct convert(varchar,Item_GenName) from ItemMasterlistTable where datalength(Item_GenName) != 0";
            SqlConnection con_db = new SqlConnection(constring);
            SqlCommand cmd = new SqlCommand(query, con_db);
            SqlDataReader reader;

            try
            {
                DataTable gencombo = new DataTable();
                con_db.Open();
                reader = cmd.ExecuteReader();
                gencombo.Load(reader);
                foreach (DataRow row in gencombo.Rows)
                {
                 Item_GenName.Items.Add(row["Item_GenName"]);
                }
                Item_GenName.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
                Item_GenName.AutoCompleteSource = AutoCompleteSource.ListItems;


            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

What I have tried:

Before it prompted this error, my sql was simply just

select Item_GenName from ItemMasterlist

I wanted it to retrieve non-empty and non-duplicate items that's why I resulted to that query.