jdbc根据考号查找学生信息，若数据库不存在这个考号输出查无此人
public static void selectExamCard(){
try {
Scanner sc = new Scanner(System.in);
System.out.println("请输入准考证号码：");
String examID = sc.next();
//建立连接
conn = DBconn.getConnection();
//预编译SQL语句
String sql = "select * from examstudent where ExamCard = ?";
ps = conn.prepareStatement(sql);
//填充占位符
ps.setString(1,examID);
//返回结果集
ResultSet rs = ps.executeQuery();
//处理结果集
while(rs.next()){
System.out.println("========查询结果========");
int id=rs.getInt("FlowID");
String type=rs.getString("Type");
String idCard=rs.getString("IDCard");
String examCard=rs.getString("ExamCard");
String studentNmae=rs.getString("StudentNmae");
String location=rs.getString("Location");
String grade=rs.getString("Grade");
System.out.println("流水号："+id+"\n"+"四六级："+type+"\n"+"身份证号："+idCard+"\n"+"准考证号："+examCard+"\n"+"学生姓名："+studentNmae+"\n"+"区域："+location+"\n"+"成绩："+grade);
}
} catch (Exception e) {
e.printStackTrace();
}finally{
DBconn.closeResouces(conn, ps, rs);
}
