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(); } } } }