CNSA-212-Personal/Database2/frmTest.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

using System.Configuration;
using System.Collections;
using System.Data.SqlClient;

namespace Database2
{
    public partial class frmTest : Form
    {
        public frmTest()
        {
            InitializeComponent();
        }

        private void cboTest_SelectedIndexChanged(object sender, EventArgs e)
        {
            SqlConnection connString = null;
            var myStudentID = "";
            var myQuery = "";

            if (cboTest.IsHandleCreated && cboTest.Focused)
                try
                {
                    //retrieve the student id
                    myStudentID = cboTest.SelectedValue.ToString().Trim();
                    myQuery = "SELECT student_id, fname, lname, acct_bal, dob FROM student WHERE student_id = '" +
                              myStudentID + "'";

                    //create the connection string
                    connString =
                        new SqlConnection(
                            "server=74.37.2.53; initial catalog=College2; connect timeout=30; User ID=admin;Password=password;");
                    //sql command
                    var cmdString = new SqlCommand();

                    connString.Open(); //open the connection
                    //clear any parameters
                    cmdString.Parameters.Clear();
                    //link the connection
                    cmdString.Connection = connString;
                    //create the command type
                    cmdString.CommandType = CommandType.Text;
                    //set the timeout
                    cmdString.CommandTimeout = 1500;
                    //set the command text
                    cmdString.CommandText = myQuery;

                    //adapter and dataset
                    var adapter = new SqlDataAdapter();
                    adapter.SelectCommand = cmdString;
                    var ds = new DataSet();
                    adapter.Fill(ds);

                    //check to see if any record is returned
                    if (ds.Tables[0].Rows.Count > 0)
                    {
                        dgvStudents.Visible = true;
                        //get data source
                        dgvStudents.DataSource = ds.Tables[0];
                        //adjust aesthetics
                        dgvStudents.AlternatingRowsDefaultCellStyle.BackColor = Color.LightGreen;
                        // Set the row and column header styles.
                        dgvStudents.ColumnHeadersDefaultCellStyle.ForeColor = Color.White;
                        dgvStudents.ColumnHeadersDefaultCellStyle.BackColor = Color.Green;
                        dgvStudents.ColumnHeadersDefaultCellStyle.Font = new Font(dgvStudents.Font, FontStyle.Bold);
                    }
                    else
                    {
                        dgvStudents.Visible = false;
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
                finally
                {
                    //close the connection
                    connString.Close();
                }
        }

        private void dgvStudents_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {
            
            
            
        }

        private void frmTest_Load(object sender, EventArgs e)
        {

            SqlConnection connString = null;

            try
            {
                //hide the data grid
                dgvStudents.Visible = false;

                //create the connection string
                connString = new SqlConnection("server=74.37.2.53; initial catalog=College2; connect timeout=30; User ID=admin;Password=password;");
                SqlCommand cmdString = new System.Data.SqlClient.SqlCommand();

                //open the connection
                connString.Open();
                cmdString.Connection = connString;

                //clear any parameters
                cmdString.Parameters.Clear();
                //link the connection
                cmdString.Connection = connString;
                //create the command type
                cmdString.CommandType = CommandType.Text;
                //set the timeout
                cmdString.CommandTimeout = 1500;

                //create and execute SQL statement
                cmdString.CommandText = "SELECT student_id,fname, lname, fname + ' ' + lname as fullname, acct_bal, dob FROM student;"; //query

                //create data adapter
                SqlDataAdapter adapter = new SqlDataAdapter();
                adapter.SelectCommand = cmdString;

                //create and fill dataset
                DataSet ds = new DataSet();
                adapter.Fill(ds);

                //get data source
                //load combo boxes
                cboTest.DataSource = ds.Tables[0];
                cboTest.ValueMember = "STUDENT_ID";
                cboTest.DisplayMember = "fullname";
                cboTest.SelectedIndex = -1; //Do not select any item

       
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            finally
            {
                connString.Close();
            }
            
        }
    }
}