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数据库增删改查

2021-11-11 23:02:14 阅读：159 来源： 互联网

标签：数据库改查 javax sql 增删 import servlet public out

主页，依靠链接条装置各个功能的HTML页面

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<a href="add.html">添加</a><br>
<a href="delete.html">删除</a><br>
<a href="change.html">修改</a><br>
<a href="search.html">查询</a><br>
</body>
</html>

增添

数据库添加 Javaweb - sdkfn - 博客园 (cnblogs.com)

删除

在HTML页面中输入要删除人的学号进行删除

HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
输入要删除的人的学号
<form name="delete" action="/qizhongzuoye/delete" mothod="post">
<input name="ID" type="text" maxlength="8" onkeyup ="value=value.replace(/[^\d]/g,'')"><br>
<input type="submit" value="提交" />
<input type="reset" value="重置" />
</form>
</body>
</html>

servlet

package servelet;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import sql_conn.*;
import bean.*;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.rowset.serial.SerialException;
@WebServlet("/delete")
public class delete extends HttpServlet{
public delete() {
super();
}
public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException {
response.setContentType("text/html");
response.setCharacterEncoding("utf-8");
request.setCharacterEncoding("utf-8");
sql_conn lj=new sql_conn();
bean xinxi=new bean();
xinxi.setID(request.getParameter("ID"));
try {
lj.lianjie().executeUpdate("delete from "+lj.getTablename()+" where ID='"+xinxi.getID()+"';");
System.out.println("删除成功！");
PrintWriter out=response.getWriter();
out.println("数据以删除<br><a href=\"homepage.html\">返回上一页</a>");
out.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
PrintWriter out=response.getWriter();
out.println("数据未删除<br><a href=\"homepage.html\">返回上一页</a>");
out.close();
e.printStackTrace();
}
lj.closethis();
}
public void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException {
doGet(request,response);
}
public void init(ServletConfig servletconfig) {

}
public void destroy() {

}
public ServletConfig getServletConfig() {
return null;
}
public String getServletinfo() {
return null;
}
}

修改，先输入要修改的人的学号，然后在下方输入修改后的信息

HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form name="enetering" action="/qizhongzuoye/change" method="post">
输入要修改的学号
<input name="ID" type="text" maxlength="8" onkeyup = "value=value.replace(/[^\d]/g,'')"><br>
输入修改后的信息<br>
<table border="1">
<tr>
<td>姓名</td>
<td><input name="name" type="text"></td>
</tr>
<tr>
<td>学生类别</td>
<td><input name="stutype" type="radio" value="本科生">本科生<input name="stutype" type="radio" value="本科生">研究生</td>
</tr>
<tr>
<td>院系</td>
<td><input name="stuc" type="text" list="sc"><datalist id="sc"><option>土木学院</option><option>机械学院</option><option>交通学院</option><option>信息学院</option><option>经管学院</option></datalist></td>
</tr>
<tr>
<td>联系电话</td>
<td><input name="phone" type="text" maxlength="11" onkeyup = "value=value.replace(/[^\d]/g,'')"></td>
</tr>
<tr>
<td>健康码颜色</td>
<td><input name="color" type="radio" value="绿码">绿码<input name="color" type="radio" value="黄码">黄码<input name="color" type="radio" value="红码">红码</td>
</tr>
<tr>
<td>行程统计</td>
<td><input name="route" type="checkbox" value="10月30日去过人民医院">10月30日去过人民医院<br>
<input name="route" type="checkbox" value="10月25日以来去过深泽县人民医院">10月25日以来去过深泽县人民医院<br>
<input name="route" type="checkbox" value="10月16日以来去过深泽县庄泽村">10月16日以来去过深泽县庄泽村<br>
<input name="route" type="checkbox" value="10月29日以来去过黑龙江哈尔滨市或者黑河市">10月29日以来去过黑龙江哈尔滨市或者黑河市<br>
<input name="route" type="checkbox" value="10月18日以来途径贵州遵义市；北京丰台、昌平">10月18日以来途径贵州遵义市；北京丰台、昌平<br>
<input name="route" type="checkbox" value="10月18日以来途径贵州遵义市；北京丰台、昌平">10月17日以来到过湖南长沙；青海海东市</td>
</tr>
<tr>
<td>其他设计疫情信息</td>
<td><input name="other" type="text"></td>
</tr>
<tr>
<td><input type="submit" value="提交" /></td>
<td><input type="reset" value="重置" /></td>
</tr>
</table>
</form>
</body>
</html>

servlet

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.rowset.serial.SerialException;
@WebServlet("/change")
public class change extends HttpServlet{
public change() {
super();
}
public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException {
response.setContentType("text/html");
response.setCharacterEncoding("utf-8");
request.setCharacterEncoding("utf-8");
sql_conn lj=new sql_conn();
bean xinxi=new bean();
xinxi.setName(request.getParameter("name"));
xinxi.setID(request.getParameter("ID"));
xinxi.setStutype(request.getParameter("stutype"));
xinxi.setStuc(request.getParameter("stuc"));
xinxi.setPhone(request.getParameter("phone"));
xinxi.setColor(request.getParameter("color"));
xinxi.setRoute(request.getParameterValues("route"));
xinxi.setOther(request.getParameter("other"));
try {
lj.lianjie().executeUpdate("update "+lj.getTablename()+" set name =\'"+xinxi.getName()+"\', stutype=\'"+xinxi.getStutype()+"\', stuc=\'"+xinxi.getStuc()+"\', phone=\'"+xinxi.getPhone()+"\', color=\'"+xinxi.getColor()+"\', route=\'"+xinxi.getRoute()+"\', other=\'"+xinxi.getOther()+"\' where ID=\'"+xinxi.getID()+"\';");
System.out.println("修改成功！");
PrintWriter out=response.getWriter();
out.println("数据以修改<br><a href=\"homepage.html\">返回上一页</a>");
out.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
PrintWriter out=response.getWriter();
out.println("数据未修改<br><a href=\"homepage.html\">返回上一页</a>");
out.close();
e.printStackTrace();
}
lj.closethis();
}
public void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException {
doGet(request,response);
}
public void init(ServletConfig servletconfig) {

}
public void destroy() {

}
public ServletConfig getServletConfig() {
return null;
}
public String getServletinfo() {
return null;
}
}

查询，在HTML输入要查询的学号，提交后将显示信息

HTML

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form name="enetering" action="/qizhongzuoye/search" method="post">
输入要查找的学号<input name="ID" type="text" maxlength="8" onkeyup = "value=value.replace(/[^\d]/g,'')"><br>
<input type="submit" value="提交" />
<input type="reset" value="重置" />
</form>
</body>
</html>

servlet

@WebServlet("/search")
public class search extends HttpServlet{
public search() {
super();
}
public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException {
response.setContentType("text/html");
response.setCharacterEncoding("utf-8");
request.setCharacterEncoding("utf-8");
sql_conn lj=new sql_conn();
bean xinxi=new bean();
ResultSet rs=null;
xinxi.setID(request.getParameter("ID"));
try {
rs=lj.lianjie().executeQuery("select * from "+lj.getTablename()+" where id='"+xinxi.getID()+"';");
System.out.println("查询成功！");
PrintWriter out=response.getWriter();
rs.next();
out.println("<table border=\"1\">");
out.println("<tr><td>姓名</td><td>"+rs.getString("name")+"</td></tr>");
out.println("<tr><td>学号</td><td>"+rs.getString("ID")+"</td></tr>");
out.println("<tr><td>学生类别</td><td>"+rs.getString("stutype")+"</td></tr>");
out.println("<tr><td>院系</td><td>"+rs.getString("stuc")+"</td></tr>");
out.println("<tr><td>联系电话</td><td>"+rs.getString("phone")+"</td></tr>");
out.println("<tr><td>健康码颜色</td><td>"+rs.getString("color")+"</td></tr>");
out.println("<tr><td>行程统计</td><td>"+rs.getString("route")+"</td></tr>");
out.println("<tr><td>其他设计疫情信息</td><td>"+rs.getString("other")+"</td></tr>");
out.println("<br><a href=\"homepage.html\">返回上一页</a>");
out.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
PrintWriter out=response.getWriter();
out.println("查询失败<br><a href=\"homepage.html\">返回上一页</a>");
out.close();
e.printStackTrace();
}
lj.closethis();
}
public void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException {
doGet(request,response);
}
public void init(ServletConfig servletconfig) {

}
public void destroy() {

}
public ServletConfig getServletConfig() {
return null;
}
public String getServletinfo() {
return null;
}
}

标签：数据库,改查,javax,sql,增删,import,servlet,public,out
来源： https://www.cnblogs.com/duanzheng/p/15542406.html

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数据库增删改查