Issue - FieldNameLookup.GetOrdinal

Question

Hi,

To error

at System.Data.ProviderBase.FieldNameLookup.GetOrdinal(String fieldName)

at System.Data.SqlClient.SqlDataReader.GetOrdinal(String name)

at System.Data.SqlClient.SqlDataReader.get_Item(String name)

at Own_rec._Default.Page_Load(Object sender, EventArgs e)

on this line

tb_date_from.Text = reader["date_from"].ToString().Trim();

How to resolve it?

Answer 1

Make sure that the query includes the column called “date_from”.

Show details about your code from Page_Load.

Answer 2

Look at your SQL statement, get the ordinal position and match it using the proper type via the SqlDataReader via one of the methods using Get....

Here date_from is a DateTime, second column which means ordinal position 1.

var statement = "SELECT Id, date_from FROM SomeTable;";

using var cn = new SqlConnection("TODO");
using var cmd = new SqlCommand(statement, cn);

cn.Open();
SqlDataReader? reader = cmd.ExecuteReader();
reader.Read();

tb_date_from.Text = reader.GetDateTime(1).ToString(CultureInfo.InvariantCulture);

Or

var statement = "SELECT Id, date_from FROM SomeTable;";

using var cn = new SqlConnection("TODO");
using var cmd = new SqlCommand(statement, cn);

cn.Open();
SqlDataReader? reader = cmd.ExecuteReader();
reader.Read();

tb_date_from.Text = reader.GetFieldValue<DateTime>(reader.GetOrdinal("date_from")).ToString(CultureInfo.InvariantCulture);