MySql.Data.MySqlClient.SchemaProvider.LoadTableColumns C# (CSharp) Method

        private void LoadTableColumns(DataTable dt, string schema,
                                      string tableName, string columnRestriction)
        {
            string sql = String.Format("SHOW FULL COLUMNS FROM `{0}`.`{1}`",
                                       schema, tableName);
            MySqlCommand cmd = new MySqlCommand(sql, connection);

            int pos = 1;
            using (MySqlDataReader reader = cmd.ExecuteReader())
            {
                while (reader.Read())
                {
                    string colName = reader.GetString(0);
                    if (columnRestriction != null && colName != columnRestriction)
                        continue;
                    DataRow row = dt.NewRow();
                    row["TABLE_CATALOG"] = DBNull.Value;
                    row["TABLE_SCHEMA"] = schema;
                    row["TABLE_NAME"] = tableName;
                    row["COLUMN_NAME"] = colName;
                    row["ORDINAL_POSITION"] = pos++;
                    row["COLUMN_DEFAULT"] = reader.GetValue(5);
                    row["IS_NULLABLE"] = reader.GetString(3);
                    row["DATA_TYPE"] = reader.GetString(1);
                    row["CHARACTER_MAXIMUM_LENGTH"] = DBNull.Value;
                    row["CHARACTER_OCTET_LENGTH"] = DBNull.Value;
                    row["NUMERIC_PRECISION"] = DBNull.Value;
                    row["NUMERIC_SCALE"] = DBNull.Value;
                    row["CHARACTER_SET_NAME"] = reader.GetValue(2);
                    row["COLLATION_NAME"] = row["CHARACTER_SET_NAME"];
                    row["COLUMN_TYPE"] = reader.GetString(1);
                    row["COLUMN_KEY"] = reader.GetString(4);
                    row["EXTRA"] = reader.GetString(6);
                    row["PRIVILEGES"] = reader.GetString(7);
                    row["COLUMN_COMMENT"] = reader.GetString(8);
                    ParseColumnRow(row);
                    dt.Rows.Add(row);
                }
            }
        }