finding number of rows using SqlDataReader

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Hello guys,

I wanna count number of rows (for a login page which of course should exactly be 1). I am using following code which is not working:

C#

SqlCommand myCom = new SqlCommand();
    myCom.CommandText = "SELECT * FROM StudentInfo WHERE StudentID = '" + txtID.Text+"'";
    myCom.Connection = myCon;

    SqlDataReader myReader;// = SqlDataReader();

    myReader = myCom.ExecuteReader();

    int res = 0;
    while(myReader.Read())
    {   ++res;    }

    if (res == 1) {
        myReader.Read();
        lbl6.Text = "<b>Connection is:  </b>" + myCon.State;
        lbl6.Text += "<br><b>Success:  </b>Search made.";
        txtClass.Text = myReader["Class"].ToString();
        txtID.Text = myReader["StudentID"].ToString();
        txtName.Text = myReader["StudentName"].ToString();
    }
}

Posted 4-Oct-10 6:26am

AmbiguousName

Updated 4-Oct-10 7:00am

Sandeep Mewara

v2

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Abhinav S · Answer 1 · 2010-10-04T06:50:00

Solution 1

This [^] thread provides some alternate solutions.

Posted 4-Oct-10 6:50am

Abhinav S

Updated 4-Oct-10 6:51am

v2

William Jordan · Answer 2 · 2010-10-04T07:36:00

Change your code to this if you want the labels/texboxes to contain data from the first row and res to have a count of rows at the end of the loop:

XML

while(myReader.Read())
{   ++res;    
    if (res == 1) {
        lbl6.Text = "<b>Connection is:  </b>" + myCon.State;
        lbl6.Text += "<br><b>Success:  </b>Search made.";
        txtClass.Text = myReader["Class"].ToString();
        txtID.Text = myReader["StudentID"].ToString();
        txtName.Text = myReader["StudentName"].ToString();
    }
}

//At this point res will contain the record count 
//the labels & textboxes will contain the information from the first data row