增删改查.

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增删改查.

在数据先建三个表，分别是：学生表、教员表、班级表

项目中所建的文件

首页：

所有的dao方法：

package com.dao;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
ity.Bj;
ity.Teacher;
ity.Student;
import com.util.DBHelper;public class StudentDao implements IStudentDao {Connection con;PreparedStatement ps;ResultSet rs;/*** 查询所有的方法*/public List<Student> getAll() {List<Student> list = new ArrayList<Student>();try {con = Con();String sql = "select * from student";ps = con.prepareStatement(sql);rs = ps.executeQuery();while (rs.next()) {Student s = new Int(1), rs.getString(2), rs.getString(3), rs.getString(4),rs.getString(5));list.add(s);}} catch (Exception e) {e.printStackTrace();} finally {Close(con, ps, rs);}return list;}/*** 查询班级*/public List<Bj> getBj() {List<Bj> list = new ArrayList<Bj>();try {con = Con();String sql = "select * from class";ps = con.prepareStatement(sql);rs = ps.executeQuery();while (rs.next()) {Bj b = new Int(1), rs.getString(2));list.add(b);}} catch (Exception e) {e.printStackTrace();} finally {Close(con, ps, rs);}return list;}/*** 查询教员*/public List<Teacher> getJy() {List<Teacher> list = new ArrayList<Teacher>();try {con = Con();String sql = "select * from teacher";ps = con.prepareStatement(sql);rs = ps.executeQuery();while (rs.next()) {Teacher y = new Int(1), rs.getString(2));list.add(y);}} catch (Exception e) {e.printStackTrace();} finally {Close(con, ps, rs);}return list;}/*** 删除*/public int del(int sid) {try {con = Con();String sql = "delete student where sid=?";ps = con.prepareStatement(sql);ps.setInt(1, sid);int n = ps.executeUpdate();return n;} catch (Exception e) {e.printStackTrace();} finally {Close(con, ps, rs);}return 0;}/*** 增加*/public int add(Student s) {try {con = Con();String sql = "insert into student values(?,?,?,?)";ps = con.prepareStatement(sql);ps.setString(1, s.getBname());ps.setString(2, s.getYname());ps.setString(3, s.getSname());ps.setString(4, s.getSah());int n = ps.executeUpdate();return n;} catch (Exception e) {e.printStackTrace();} finally {Close(con, ps, rs);}return 0;}/*** 根据id查看*/public Student getById(int sid) {try {con = Con();String sql = "select * from student where sid=?";ps = con.prepareStatement(sql);ps.setInt(1, sid);rs = ps.executeQuery();while (rs.next()) {Student s = new Int(1), rs.getString(2), rs.getString(3), rs.getString(4),rs.getString(5));return s;}} catch (Exception e) {e.printStackTrace();} finally {Close(con, ps, rs);}return null;}/*** 修改*/public int upd(Student s) {try {con = Con();String sql = "update student set sclass=?,steacher=?,sname=?,sah=? where sid=?";ps = con.prepareStatement(sql);ps.setString(1, s.getBname());ps.setString(2, s.getYname());ps.setString(3, s.getSname());ps.setString(4, s.getSah());ps.setInt(5, s.getSid());int n = ps.executeUpdate();return n;} catch (Exception e) {e.printStackTrace();} finally {Close(con, ps, rs);}return 0;}/*** 模糊查询*/public List<Student> getAll(String jy, String bj, String ah) {List<Student> list = new ArrayList<Student>();try {con = Con();String sql = "select * from student where sclass like ? and steacher like ? and sah like ?";ps = con.prepareStatement(sql);ps.setString(1, "%" + bj + "%");ps.setString(2, "%" + jy + "%");ps.setString(3, "%" + ah + "%");rs = ps.executeQuery();while (rs.next()) {Student s = new Int(1), rs.getString(2), rs.getString(3), rs.getString(4),rs.getString(5));list.add(s);}} catch (Exception e) {e.printStackTrace();} finally {Close(con, ps, rs);}return list;}
}

增加界面

添加成功点确定会跳入主界面

add.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" ".dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title><style type="text/css">
table,tr{
border-collapse: collapse;
}
td{
text-align: center;
}</style>
</head>
<body>
<h3 align="center">新增页面</h3>
<form action="add.do">
<table border="" width="500px" height="400px" align="center">
<tr>
<td>名字 </td>
<td><input type="text" name="sname"></td>
</tr>
<tr>
<td>教员:</td>
<td>
<select name="yname">
<option value="">--请选择教员--</option>
<option value="张哥">张哥</option>
<option value="李哥">李哥</option>
<option value="王哥">王哥</option>
<option value="赵哥">赵哥</option>
</select>
</td>
</tr>
<tr>
<td>班级:</td>
<td>
<select name="bname">
<option value="">--请选择班级--</option>
<option value="一班">一班</option>
<option value="二班">二班</option>
<option value="三班">三班</option>
<option value="四班">四班</option>
</select>
</td>
</tr>
<tr>
<td>
爱好:</td>
<td>
<input type="checkbox" name="sah" value="篮球" >篮球
<input type="checkbox" name="sah" value="足球" >足球
<input type="checkbox" name="sah" value="唱歌" >唱歌
<input type="checkbox" name="sah" value="跳舞" >跳舞
</td>
</tr>
<tr>
<td>按键</td><td><button>确认</button> <input type="reset"/></td>
</tr>
</table></form>
<h3 align="center"><a href="index.do">返回首页</a></h3></body>
</html>

addservler

package com.servlet;import java.io.IOException;
import java.io.PrintWriter;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import com.dao.IStudentDao;
import com.dao.StudentDao;
ity.Student;/*** Servlet implementation class AddServlrt*/
@WebServlet("/add.do")
public class AddServlrt extends HttpServlet {private static final long serialVersionUID = 1L;/*** @see HttpServlet#HttpServlet()*/public AddServlrt() {super();// TODO Auto-generated constructor stub}/*** @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)*/protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}/*** @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)*/protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.setCharacterEncoding("utf-8");response.setContentType("text/html;charset=utf-8");String sname&#Parameter("sname");String yname&#Parameter("yname");String bname&#Parameter("bname");String[] ah&#ParameterValues("sah");String sah = "" ;for (String a : ah) {sah+=a+",";}Student s=new Student(0, bname, yname, sname, sah);IStudentDao isb=new StudentDao();int i = isb.add(s);PrintWriter out = Writer();if(i>0) {out.print("<script>alert('增加成功');location.href='index.do'</script>");}else {out.print("<script>alert('增加失败');location.href='index.do'</script>");}}}

删除

在删除时会确认一遍你是否要删除，防止误删

点完确定后会显示删除成功

删除成功后跳入主界面

delServlet

package com.servlet;import java.io.IOException;
import java.io.PrintWriter;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import com.dao.IStudentDao;
import com.dao.StudentDao;/*** Servlet implementation class DelServlet*/
@WebServlet("/del.do")
public class DelServlet extends HttpServlet {private static final long serialVersionUID = 1L;/*** @see HttpServlet#HttpServlet()*/public DelServlet() {super();// TODO Auto-generated constructor stub}/*** @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)*/protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}/*** @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)*/protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.setCharacterEncoding("utf-8");response.setContentType("text/html;charset=utf-8");PrintWriter out = Writer();int tid=Integer.Parameter("sid"));IStudentDao isb=new StudentDao();int n=isb.del(tid);if(n>0) {out.print("<script>alert('删除成功');location.href='index.do'</script>");}else {out.print("<script>alert('删除失败');location.href='index.do'</script>");}}}

修改

修改前：

修改的界面：

修改成功后会跳入主界面

upd jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri=""%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" ".dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title><style type="text/css">
table, tr {border-collapse: collapse;
}td {text-align: center;
}
</style></head>
<body><h3 align="center">修改页面</h3><form action="upd.do"><table border="" width="500px" height="400px" align="center"><input type="hidden" name="sid" value="${s.sid}"><td>名字</td><td><input type="text" name="sname" value="${s.sname }"></td></tr><tr><td>教员:</td><td><select name="yname"><option value="张哥" ${s.yname=="张哥"?"selected":"" }>张哥</option><option value="李哥" ${s.yname=="李哥"?"selected":"" }>李哥</option><option value="王哥" ${s.yname=="王哥"?"selected":"" }>王哥</option><option value="赵哥" ${s.yname=="赵哥"?"selected":"" }>赵哥</option></select></td></tr><tr><td>班级:</td><td><select name="bname"><option value="一班" ${s.bname=="一班"?"selected":"" }>一班</option><option value="二班" ${s.bname=="二班"?"selected":"" }>二班</option><option value="三班" ${s.bname=="三班"?"selected":"" }>三班</option><option value="四班" ${s.bname=="四班"?"selected":"" }>四班</option></select></td></tr><tr><td>爱好:</td><td><input type="checkbox" name="sah" value="篮球"<c:forEach var="i" items="${ ah }"><c:if test="${ i=='篮球' }"> checked</c:if></c:forEach>>篮球<input type="checkbox" name="sah" value="足球"<c:forEach var="i" items="${ ah }"><c:if test="${ i=='足球' }"> checked</c:if></c:forEach>>足球<input type="checkbox" name="sah" value="唱歌"<c:forEach var="i" items="${ ah }"><c:if test="${ i=='唱歌' }"> checked</c:if></c:forEach>>唱歌<input type="checkbox" name="sah" value="跳舞"<c:forEach var="i" items="${ ah }"><c:if test="${ i=='跳舞' }"> checked</c:if></c:forEach>>跳舞</td></tr><tr><td>按键</td><td><button>确认修改</button></td></tr></table></form><h3 align="center"><a href="index.do">返回首页</a></h3>
</body>
</html>

updservlet

package com.servlet;import java.io.IOException;
import java.io.PrintWriter;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import com.biz.IXsBao;
import com.biz.XsBao;
import com.dao.IStudentDao;
import com.dao.StudentDao;
ity.Student;/*** Servlet implementation class UpdServlet*/
@WebServlet("/upd.do")
public class UpdServlet extends HttpServlet {private static final long serialVersionUID = 1L;/*** @see HttpServlet#HttpServlet()*/public UpdServlet() {super();// TODO Auto-generated constructor stub}/*** @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)*/protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}/*** @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)*/protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.setCharacterEncoding("utf-8");response.setContentType("text/html;charset=utf-8");String sname&#Parameter("sname");String yname&#Parameter("yname");String bname&#Parameter("bname");String[] ah&#ParameterValues("sah");String sah = "" ;for (String a : ah) {sah+=a+",";}int sid=Integer.Parameter("sid"));Student s=new Student(sid, bname, yname, sname, sah);IStudentDao isb=new StudentDao();int i = isb.upd(s);PrintWriter out = Writer();if(i>0) {out.print("<script>alert('修改成功');location.href='index.do'</script>");}else {out.print("<script>alert('修改失败');location.href='index.do'</script>");}}}

查询

可以查询所有、查询班级、查询教员

还可以根据id进行查询，也可以进行模糊查询

本文发布于:2024-02-04 07:54:26，感谢您对本站的认可！

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