此次Java课程有学长为我们讲解了关于数据库的建造,对数据库的导入导出有了一定程度上的了解。
对数据库的连接和增删改查使用可查看:https://www.bilibili.com/video/av30839320/?p=20
数据库相关内容下载可查看网址:https://www.vipkes.cn/service.jsp 关注公众号可查看具体安装步骤(获取验证码获得公众号)
以下是关于此次课程的学习:
首先应该用JDBC连接数据库,使用eclipse成功连接数据库:
util.java
package ke; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class util { String user="sa"; String password="zb753951";
//liusy数据库名称 user后为数据库名称 password为密码根据实际情况更改 String url="jdbc:mysql://localhost:3306/liusy?" + "user=root&password=15075289483&useUnicode=true&characterEncoding=UTF8&serverTimezone=GMT%2B8&useSSL=false"; public Connection getConn(){ Connection conn=null; try { Class.forName("com.mysql.jdbc.Driver"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { conn=DriverManager.getConnection(url, user, password); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } return conn; } public void close(ResultSet rs, Statement state, Connection conn) { if(rs!=null) { try { rs.close(); } catch(SQLException e) { e.printStackTrace(); } } if(state!=null) { try { state.close(); } catch(SQLException e) { e.printStackTrace(); } } if(conn!=null) { try { conn.close(); } catch(SQLException e) { e.printStackTrace(); } } } }
然后调用连接编写对数据库的增删改查:
Test.java
package ke; import java.sql.*; import java.util.Scanner; public class Test { public static void main(String[] args) { System.out.println("��������ҿγ̣�"); String a; Scanner scan = new Scanner(System.in); a = scan.next(); find(a); } static Connection conn; static PreparedStatement ps = null; static ResultSet rs; static String sql = "select * from Ke_c"; static util ut = new util(); static Scanner in = new Scanner(System.in); static String Ke; static String Tea; static String Di; public static String a_Ke() { return Ke; } public static String a_Tea() { return Tea; } public static String a_Di() { return Di; } public static int add(String ke, String teacher, String where) { conn = ut.getConn(); String sql = "insert into kecheng values(?,?,?)"; int b = 0; try { ps = conn.prepareStatement(sql); ps.setString(1, ke); ps.setString(2, teacher); ps.setString(3, where); int a = ps.executeUpdate(); if (a > 0) { b++; System.out.println("��ӳɹ�"); } else { System.out.println("���ʧ��"); } } catch (Exception e) { e.printStackTrace(); } try { if (ps != null) ps.close(); if (conn != null) conn.close(); } catch (Exception e2) { e2.printStackTrace(); } return b; } public static int uqdate(String ke, String teacher, String where) { int b = 0; conn = ut.getConn(); ps = null; sql = "update kecheng set teacher=?,where=? where ke=?"; try { ps = conn.prepareStatement(sql); ps.setString(1, teacher); ps.setString(2, where); ps.setString(3, ke); int a = ps.executeUpdate(); if (a > 0) { b++; System.out.println("�ijɹ�"); } else { System.out.println("��ʧ��"); } } catch (Exception e) { e.printStackTrace(); } try { if (ps != null) ps.close(); if (conn != null) conn.close(); } catch (Exception e2) { e2.printStackTrace(); } return b; } public static int delete(String Ke) { int b = 0; conn = ut.getConn(); ps = null; sql = "delete from kecheng where ke=?"; try { ps = conn.prepareStatement(sql); ps.setString(1, Ke); int a = ps.executeUpdate(); if (a > 0) { b++; System.out.println("ɾ���ɹ�"); } else { System.out.println("ɾ��ʧ��"); } } catch (Exception e) { e.printStackTrace(); } try { if (ps != null) ps.close(); if (conn != null) conn.close(); } catch (Exception e2) { e2.printStackTrace(); } return b; } public static void find(String a) { conn = ut.getConn(); ps = null; ResultSet rs = null; String id; sql = "select * from kecheng where ke=?"; try { ps = conn.prepareStatement(sql); ps.setString(1, a); rs = ps.executeQuery(); if (rs.next()) { Ke = rs.getString("ke"); Tea = rs.getString("teacher"); Di = rs.getString("where" + ""); } } catch (SQLException e) { e.printStackTrace(); } finally { try { if (ps != null) ps.close(); if (conn != null) conn.close(); } catch (Exception e2) { e2.printStackTrace(); } } } }
主函数调用
<%@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Insert title here</title> </head> <body> <a href = "add.jsp">增加</a></br> <a href = "find.jsp">查询 </a></br> <a href = "delete.jsp">删除</a></br> <a href = "update.jsp">修改</a></br> </body> </html>
增:
<%@page import="ke.Test"%> <%@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>增加</title> <script type="text/javascript""> function validate() { var Ke=document.forms[0].Ke.value; var Tea=document.forms[0].Tea.value; var Di=document.forms[0].Di.value; if(Ke.length<=0){ alert("课程不能为空,请输入课程!"); return false; } else if(Tea.length<=0){ alert("教师不能为空,请输入教师姓名!"); return false; } else if(age<=0){ alert("地点不能为空,请输入地点!"); return false; } else if(Di.length<=0){ alert("专业不能为空,请输入所学专业!"); return false; } else{ return true; } //document.getElementById("form").submit(); } </script> </head> <body> <form action="addresult.jsp" method="post" id="form" onSubmit="return validate()" > +++++++++++++++++------------------------------------------------------------------------------------------------------------------------------------------------- <input type="hidden" name="methodName" value="0"/> <h4> 课程:<input type="text" name="Ke"title="课程不能为空"></input><br></h4> <h4> 任课教师:<input type="radio" name="Tea" value="Wangjianmin">王建民 <input type="radio" name="Tea" value="liulijia">刘立嘉 <input type="radio" name="Tea" value="liudan">刘丹 <input type="radio" name="Tea" value="wanghui">王辉 <input type="radio" name="Tea" value="yangziguang">杨子光 <br></h4> <h4> 上课地点:<input type="radio" name="Di" value="yijiao">一教 <input type="radio" name="Di" value="erjiao">二教 <input type="radio" name="Di" value="sanjiao">三教 <input type="radio" name="Di" value="jijiao">基教 <br></h4> <input type="submit" value="完成"/> </form> </body> </html>
<%@page import="ke.Test"%>
<%@page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>添加结果</title>
</head>
<body>
<%
out.println(request.getParameter("Ke"));
if(Test.add(request.getParameter("Ke"),request.getParameter("Tea"),request.getParameter("Di"))==1)
{
{
out.print("<script language = 'javascript'>alert('添加成功');</script>");
response.setHeader("refresh", "0;url=Zhu.jsp");
}
}
else{
out.print("<script language = 'javascript'>alert('添加失败');</script>");
response.setHeader("refresh", "0;url=Zhu.jsp");
//out.println("添加失败");
}
%>
</body>
</html>
删:
<%@page import="ke.Test"%> <%@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>删除界面</title> </head> <body> <form action="deleteresult.jsp" method="post" id="form" onSubmit="return validate()" > <input type="hidden" name="methodName" value="0"/> <h4> 课程:<input type="text" name="Ke"title="课程不能为空"></input><br></h4> <input type="submit" value="完成"/> </form> </body> </html> <%@page import="ke.Test"%> <%@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>删除结果</title> </head> <body> <% if(Test.delete(request.getParameter("Ke"))==1) { { out.print("<script language = 'javascript'>alert('添加成功');</script>"); response.setHeader("refresh", "0;url=Zhu.jsp"); } } else{ out.print("<script language = 'javascript'>alert('添加失败');</script>"); response.setHeader("refresh", "0;url=Zhu.jsp"); //out.println("添加失败"); } %> </body> </html>
改:
<%@page import="ke.Test"%> <%@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>修改界面</title> <script type="text/javascript""> function validate() { var Ke=document.forms[0].Ke.value; var Tea=document.forms[0].Tea.value; var Di=document.forms[0].Di.value; if(Ke.length<=0){ alert("课程不能为空,请输入课程!"); return false; } else if(Tea.length<=0){ alert("教师不能为空,请输入教师姓名!"); return false; } else if(age<=0){ alert("地点不能为空,请输入地点!"); return false; } else if(Di.length<=0){ alert("专业不能为空,请输入所学专业!"); return false; } else{ return true; } //document.getElementById("form").submit(); } </script> </head> <body> <form action="uqdateresult.jsp" method="post" id="form" onSubmit="return validate()" > <input type="hidden" name="methodName" value="0"/> <h4> 课程:<input type="text" name="Ke"title="课程不能为空"></input><br></h4> <h4> 任课教师:<input type="radio" name="Tea" value="Wangjianmin">王建民 <input type="radio" name="Tea" value="liulijia">刘立嘉 <input type="radio" name="Tea" value="liudan">刘丹 <input type="radio" name="Tea" value="wanghui">王辉 <input type="radio" name="Tea" value="yangziguang">杨子光 <br></h4> <h4> 上课地点:<input type="radio" name="Di" value="yijiao">一教 <input type="radio" name="Di" value="erjiao">二教 <input type="radio" name="Di" value="sanjiao">三教 <input type="radio" name="Di" value="jijiao">基教 <br></h4> <input type="submit" value="完成"/> </form> </body> </html> <%@page import="ke.Test"%> <%@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>修改结果</title> </head> <body> <% if(Test.uqdate(request.getParameter("Ke"),request.getParameter("Tea"),request.getParameter("Di"))==1) { { out.print("<script language = 'javascript'>alert('删除成功');</script>"); response.setHeader("refresh", "0;url=Zhu.jsp"); } } else{ out.print("<script language = 'javascript'>alert('删除失败');</script>"); response.setHeader("refresh", "0;url=Zhu.jsp"); //out.println("添加失败"); } %> </body> </html>
查:
<%@page import="ke.Test"%> <%@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>查找界面</title> <script type="text/javascript""> function validate() { var Ke=document.forms[0].Ke.value; var Tea=document.forms[0].Tea.value; var Di=document.forms[0].Di.value; if(Ke.length<=0){ alert("课程不能为空,请输入课程!"); return false; } else if(Tea.length<=0){ alert("教师不能为空,请输入教师姓名!"); return false; } else if(age<=0){ alert("地点不能为空,请输入地点!"); return false; } else if(Di.length<=0){ alert("专业不能为空,请输入所学专业!"); return false; } else{ return true; } //document.getElementById("form").submit(); } </script> </head> <body> <form action="findresult.jsp" method="post" id="form" onSubmit="return validate()" > <input type="hidden" name="methodName" value="0"/> <h4> 课程:<input type="text" name="Ke"title="课程不能为空"></input><br></h4> <input type="submit" value="完成"/> </form> </body> </html> <%@page import="ke.Test"%> <%@page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>查找结果</title> </head> <body> <% Test.find(request.getParameter("Ke")); out.println(Test.a_Ke()); out.println(Test.a_Tea()); out.println(Test.a_Di()); %> </body> </html>