Merging two 2 tables into 1 C# statement from sql server 2008

Question

Hi guys currently i have this code. I would like to add another field " GivenName" into the statement but the issue is it is from another table. How do i merge two database tables into this statement without altering the original query output.

namespace Test
{
    public partial class frmSales : Form
    {
        public frmSales()
        {
            InitializeComponent();
        }


        private void dtpFrom_ValueChanged(object sender, EventArgs e)
        {

        }

        private void btnExtract_Click(object sender, EventArgs e)
        {

            SqlConnection objConn = new SqlConnection("Data Source=abcdefg;Initial Catalog=hello;Persist Security Info=True;User ID=sa;Password=");

                         objConn.Open();

            SqlCommand objCmd = new SqlCommand("SELECT CONVERT(char(80), InvDate,3) AS InvDate,InvoiceNo,EmployerCode,TaxAmount + SubTotal AS Amount,'' AS Payment FROM Invoice WHERE (InvDate >= CONVERT(datetime, '" + dtpFrom.Text + "', 105 )) AND (InvDate <= CONVERT(datetime, '" + dtpTo.Text + "', 105))", objConn);

            SqlDataReader objReader;
            objReader = objCmd.ExecuteReader();

            System.IO.FileStream fs = new System.IO.FileStream("C:\\CMSExportedData\\Sales-" + DateTime.Now.ToString("dd-MM-yyyy") + ".txt", System.IO.FileMode.Create);
            System.IO.StreamWriter sw = new System.IO.StreamWriter(fs, System.Text.Encoding.Default);

            int count = 0;
            while (objReader.Read())
            {

                for (int i = 0; i < 5; i++)
                {
                    if (!objReader.IsDBNull(i))
                    {
                        string s;
                        s = objReader.GetDataTypeName(i);
                        //MessageBox.Show(s);
                        if (objReader.GetDataTypeName(i) == "char")
                        {
                            sw.Write(objReader.GetString(i));
                        }
                        else if (objReader.GetDataTypeName(i) == "money")

                        {
                            sw.Write(objReader.GetSqlMoney(i).ToString());
                        }
                        else if (objReader.GetDataTypeName(i) == "nvarchar")
                        {
                            sw.Write(objReader.GetString(i));
                        }
                    }
                    if (i < 4)
                    {
                        sw.Write("\t");
                    }

                }
                count = count + 1;
                sw.WriteLine();

            }
            sw.Flush();
            fs.Close();
            objReader.Close();
            objConn.Close();
            MessageBox.Show(count + " records exported successfully.");
            this.Close();
        }

        private void groupBox1_Enter(object sender, EventArgs e)
        {

        }

        private void dtpTo_ValueChanged(object sender, EventArgs e)
        {

        }

        private void frmSales_Load(object sender, EventArgs e)
        {

        }
    }
}

Answer 1

Change the SQL statement, so that you JOIN the 2 tables together. Then, you can access the other column.

Answer 2

Use a JOIN :

SqlCommand objCmd = new SqlCommand("SELECT CONVERT(char(80), InvDate,3) AS InvDate,InvoiceNo,EmployerCode,TaxAmount + SubTotal AS Amount,'' AS Payment 
                                    FROM Invoice inv INNER JOIN
                                         [YourOtherTable] tab ON inv.[SomeID] = tab.[SomeID]
                                    WHERE (InvDate >= CONVERT(datetime, '" + dtpFrom.Text + "', 105 )) 
                                    AND (InvDate <= CONVERT(datetime, '" + dtpTo.Text + "', 105))", objConn);

INNER JOIN if it's a NOT NULL column and LEFT JOIN when the column is NULL .

So you will add this:

FROM Invoice inv INNER JOIN
    [YourOtherTable] tab ON inv.[SomeID] = tab.[SomeID]

EDIT:

Okay, it seems that [MedicalRecordID] is the most obvious.

FROM [Invoice] inv INNER JOIN 
[PatientDetails] tab ON inv.[MedicalRecordID] = tab.[MedicalRecordID]

Just remember, if you are looking for a specific PatientDetails record you will need to add another AND to your WHERE clause.

Something like:

AND tab.[LastName] = 'SomeLastName'

EDIT:

SqlCommand objCmd = new SqlCommand("SELECT CONVERT(char(80), inv.[InvDate],3) AS InvDate
                                         , inv.[InvoiceNo]
                                         , inv.[TaxAmount] + inv.[SubTotal] AS Amount
                                         , '' AS Payment 
                                    FROM [Invoice] inv LEFT JOIN 
                                         [PatientDetails] tab ON inv.[MedicalRecordID] = tab.[MedicalRecordID] 
                                    WHERE (inv.[InvDate] >= CONVERT(datetime, '" + dtpFrom.Text + "', 105 )) 
                                    AND (inv.[InvDate] <= CONVERT(datetime, '" + dtpTo.Text + "', 105))", objConn);