无法使用 SqlDataReader c# 中的 GetSqlValues 方法

Question

I make post method to select data from sql server, it works but i cant return all the data that i select and only can get one data

   [HttpPost]
        public Object SelectData([FromBody]DataEmployee employee)
        {
            DataEmployee Data = new DataEmployee();

            string ConeectionString = "";
            using (SqlConnection openCon = new SqlConnection(ConeectionString))
            {       
                openCon.Open();

                SqlCommand command = new SqlCommand("SELECT [ID],[FirstName] ,[LastName] ,[Gender] ,[Salary] FROM[dbo].[employeesData] WHERE[FirstName]= @zip", openCon);

                command.Parameters.AddWithValue("@zip", employee.FirstName );
                int result = command.ExecuteNonQuery();
                SqlDataReader reader = command.ExecuteReader();
                // result gives the -1 output.. but on insert its 1
                if (reader.HasRows)
                {
                    Console.WriteLine("\t{0}\t{1}", reader.GetName(0),
                        reader.GetName(1));

                    if (reader.Read())
                    {
                       // Console.WriteLine("\t{0}\t{1}", reader.GetInt32(0),
                         //   reader.GetString(1));

                    }
                    //    reader.NextResult();
                 //   return reader.GetString(3);   

                }
                else
                {
                    return "Data is Empty";
                }

                return reader.GetString(2);
            }       
        }

As you can see above i use getstring to return the data and that's make i only get one specified column , in here i want return all column that i get from the query, so i look all method that available from SQL Data Reader and found GetSqlValues that will fill an array of object that contains the value from for all column in the record, but i am struggling to make it works.

I already tried return reader.GetSqlValues(Data); But it shows error message cant convert to object. Can anyone help me here i need to return all column here

Answer 1

You can do it like below :

string val="";
if (reader.HasRows)
{
    while (reader.Read())
    {
        val += "ID = " + reader[0].ToString() + "; Name = " + reader[1].ToString();
    }
}
else
{
    return "Data is Empty";
}

reader.Close();
return val;

If you know the column name to show, then you can use it :

while (reader.Read())
{
    Console.WriteLine("\t{0}\t{1}", reader["ColumnOneName"].ToString(),
    reader["ColumnTwoName"].ToString());
}

Answer 2

To return all columns and all rows returned from the query.

int count = reader.FieldCount;
List<List<string>> data = new List<List<string>>();
while(reader.Read()) {
    data.Add(Enumerable.Range(0,count -1).Select(it => reader.GetValue(it)));    
}