studentdao.java~70~

简单的信息录入系统 大家可以在这个基础上将其完善 是对初学者的有力帮助

package mvcdemo;

import java.sql.*;
import com.sun.rowset.*;
import javax.sql.rowset.CachedRowSet;
import java.util.Vector;

public class StudentDAO {
    public StudentDAO() {
    }

    public static int insert(Student s) {
        int result = 0;
        //创建insert  sql语句
        //String sql = "insert stuTbl values("+s.getId()+",'"+s.getName()+
        //             "','"+s.getSex()+"',"+s.getAge()+",'"+s.getAddr()+"')";
        String sql = "insert stuTbl values(%s,'%s','%s',%s,'%s')";
        String[] a = {s.getId() + "", s.getName(), s.getSex(), "" + s.getAge(),
                     s.getAddr()};
        sql = String.format(sql, a);
        //调用daoHelper执行该语句
        DAOHelper dh = new DAOHelper();
        result = dh.nonQuery(sql);
        return result;
    }

    public static int delete(int id) {
        int result = 0;
        String sql = "delete from stuTbl where sid=%s";
        String[] a = {id + ""};
        sql = String.format(sql, a);
        //调用daoHelper执行该语句
        DAOHelper dh = new DAOHelper();
        result = dh.nonQuery(sql);

        return result;
    }

    public static int update(Student s) {
        int result = 0;
        String sql =
                "update stuTbl set sname='%s',sex='%s',age=%s,addr='%s' where sid=%s";
        String[] a = {s.getName(), s.getSex(), "" + s.getAge(), s.getAddr(),
                     s.getId() + ""};
        sql = String.format(sql, a);
        //调用daoHelper执行该语句
        DAOHelper dh = new DAOHelper();
        result = dh.nonQuery(sql);
        return result;
    }

    public static Student select(int id) {
        Student s = null;
        String strSQL = "select * from stuTbl where sid=%s";
        String[] str = {"" + id};
        strSQL = String.format(strSQL, str);
        DAOHelper dh = new DAOHelper();
        try {
            CachedRowSet crs = dh.query(strSQL);
            if (crs.next()) {
                s = new Student();
                s.setId(crs.getInt(1));
                s.setName(crs.getString(2));
                s.setSex(crs.getString(3));
                s.setAge(crs.getInt(4));
                s.setAddr(crs.getString(5));
            }
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
        return s;
    }

    public static Vector select() {
        Vector vData = new Vector();
        String sql = "select * from stuTbl";
        DAOHelper dh = new DAOHelper();
        CachedRowSet crs = dh.query(sql);
        while (crs.next()) {
            Vector vRow = new Vector();
            for (int i = 1; i <= 5; i++) {
                vRow.add(crs.getString(i));
            }
        }
        return vData;
    }

}