Can we use return rdr using a stored procedure in C#?

Question

I have table as follows

emp_id, emp_name, emp_address, emp_salary, emp_rating

I would like to get all the above rows ... I have written stored procedure as follows:

CREATE PROCEDURE [dbo].[fetch_empdata]
@empid int
AS
SELECT * 
FROM emptable
WHERE emp_id = @empid;

string connection = "Data Source=" + server + ";Initial Catalog=" + dbase + ";User ID=" + userid + ";Password=" + password;

conn = new SqlConnection(connection);
conn.Open();
SqlCommand cmd  = new SqlCommand(storedprocedure, conn);

cmd.CommandType = CommandType.StoredProcedure;

cmd.Parameters.Add(new SqlParameter("@empid", empid));

rdr = cmd.ExecuteReader();

Is there a way to use a command return rdr? I would like to return all the values of this table to some other class. Or do I have to explicitly move var empid = rdr("EMPID")?

Answer 1

according to msdn you are doing it right, if you are setting your variable storedprocedure to the value "fetch_empdata"

Then, to get the value, you could do

if(rdr.Read()) {
    string emp_id = rdr.GetString(0);
}

being 0 the index of your "EMPID" column

EDIT: A good thing to keep in mind is the fact that you are using SELECT * to retrieve data, which is not a good practice, as any change in the table columns will result in a change in the select return, and could also break your application.

A good approach would be to explicitly inform which columns you want to return, and the order of them, such as

SELECT EMPID, EMPNAME, ...

Answer 2

Once you get your SqlDataReader like this:

rdr = cmd.ExecuteReader();

you now need to enumerate over the result set:

while(rdr.Read())
{
    int emp_id = rdr.GetInt(0);
    string emp_name = rdr.GetString(1);
    string emp_address = rdr.GetString(2);
    decimal emp_salary = rdr.GetDecimal(3);
    int emp_rating = rdr.GetInt(4);

    // do something with those variables.... then move on to next row
}

What you do with those variables is entirely up to you - whatever makes sense for you. Stick them into an object and put all objects retrieved into a List<Employee> or something - whatever you want.

Also: you might need to check for NULL values, too - before calling .GetString/.GetInt etc. - otherwise you'll get an exception.