private void Submit_Click(object sender, EventArgs e) { if (Validate_Form()) { DateTime today = DateTime.Today; SQL_Operator sql_operator = new SQL_Operator(); int graduation_year = today.Year + 4; string sqlQuery = null; if (YesButton.Checked) { sqlQuery = "INSERT INTO STUDENT_INFO (usn, name, dob, graduation_year, hostel_id) VALUES ('" + USNBox.Text.ToUpper() + "', '" + NameBox.Text.ToUpper() + "', DATE '" + DOBBox.Text + "', " + graduation_year + ", HOSTEL_ID_SEQUENCE.NEXTVAL)"; } else { sqlQuery = "INSERT INTO STUDENT_INFO (usn, name, dob, graduation_year) VALUES ('" + USNBox.Text.ToUpper() + "', '" + NameBox.Text.ToUpper() + "', DATE '" + DOBBox.Text + "', " + graduation_year + ")"; } if (sql_operator.Insert(sqlQuery)) { MessageBox.Show("Inserted Entry", "Successful"); Clear_All_Entries(); } else { MessageBox.Show("USN Must Be Unique", "Failed"); } } }