Command Object’s ExecuteNonQuery Method ISYS 512

Using ExecuteNonQuery Method To run SQL: Insert Delete Update The ExecuteNonQuery method also returns a value indicating the number of records affected by the SQL statement.

Use ExecuteNonQuery to Insert A New Record Create unbound text boxes to enter new customer record. string strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\CSharpexamples\\SalesDB2011.accdb"; OleDbConnection objConn = new OleDbConnection(strConn); string strSQLInsert; strSQLInsert = "Insert into Customer values ('"; strSQLInsert += textBox1.Text + "','" + textBox2.Text + "','"; strSQLInsert += textBox3.Text + "','" + textBox4.Text + "')"; OleDbCommand objCommInsert= new OleDbCommand(strSQLInsert, objConn); objConn.Open(); MessageBox.Show(strSQLInsert.ToString()); try { objCommInsert.ExecuteNonQuery(); } catch (Exception ex) MessageBox.Show(ex.Message); objConn.Close();

Use ExecuteNonQuery to Delete A New Record Create a listbox with CIDs Delete the selected record and remove the CID from the listbox. string strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\CSharpexamples\\SalesDB2011.accdb"; OleDbConnection objConn = new OleDbConnection(strConn); string strSQL = "delete from customer where cid = '" + listBox1.SelectedItem + "'"; OleDbCommand objComm = new OleDbCommand(strSQL, objConn); try { int affectedRecords; objConn.Open(); affectedRecords= objComm.ExecuteNonQuery(); MessageBox.Show(affectedRecords.ToString() + "records deleted"); listBox1.Items.RemoveAt(listBox1.SelectedIndex); } catch (System.Exception ex) MessageBox.Show(ex.Message); objConn.Close();

Use ExecuteNonQuery to Update A New Record Create a project that do the following tasks: Use a DataReader to retrieve customer IDs and populate a listbox. Select a new rating from radio buttons for the selected customer. Update customer’s rating using the ExecuteNonQuery method of a Command object. , fa n

create CID listbox: private void Form4_Load(object sender, EventArgs e) { string strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\CSharpexamples\\SalesDB2011.accdb"; OleDbConnection objConn = new OleDbConnection(strConn); string strSQL = "select cid from customer;"; OleDbCommand objComm = new OleDbCommand(strSQL, objConn); try objConn.Open(); OleDbDataReader objDataReader; objDataReader = objComm.ExecuteReader(); while (objDataReader.Read() == true) listBox1.Items.Add(objDataReader["cid"]); } catch (System.Exception ex) MessageBox.Show(ex.Message); objConn.Close();

Update customer rating: private void button1_Click(object sender, EventArgs e) { string newRating; if (radioButton1.Checked) newRating = "A"; } else if (radioButton2.Checked) newRating = "B"; else newRating = "C"; string strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\CSharpexamples\\SalesDB2011.accdb"; OleDbConnection objConn = new OleDbConnection(strConn); string strSQL = "Update customer set rating = '" + newRating + "' where cid='" + listBox1.SelectedItem + "'"; OleDbCommand objComm = new OleDbCommand(strSQL, objConn); try objConn.Open(); objComm.ExecuteNonQuery(); catch (System.Exception ex) MessageBox.Show(ex.Message); objConn.Close();