JSP如何检验数据库操作成功啊?
新手请教,如何在JSP中检验对数据库的操作(如增加,删除,修改)成功了?能给点代码示例么?
谢谢
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数据库 JSP 检验
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好象有说可以再查询一次的
但还是没搞懂原理
[此贴子已经被作者于2007-6-2 15:32:05编辑过]
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例如:
private Statement stmt = null;
int j = 0;
j = stmt.executeUpdate(sql); //stmt.executeUpdate(sql)如果成功,返回1,否则返回0.
if(j != 0){
说明添加成功
}else{
添加失败.
}
增加,删除,修改一样.
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执行了就算成功了 !!
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最好写一个类
1.setConn()方法,返回boolean值
boolean b=false;
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection conn=DriverManager.getConnection("jdbc:odbc:xxx");
Statement st=conn.createStatement();
b=true;
}
...
2.closeConn()方法
略
3.getSelect(String sql)方法,返回ResultSet 类型值,否则返回空
4.doUpdate(String sql)方法,返回boolean值
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在jsp 中new 一个这个类,通过调用这些方法,可以判断b的真假以及结果集的空否,就知道是否成功
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试了
MS不成功
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用异常判断,异常不执行就成功了.不知是否是你想知道的.
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打开数据库看看就知道成功没成功了吧
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一般数据库的操作都用到异常判断,不成功就抛出异常。
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package student;
import java.sql.*;
public class stuBean1{
Connection con = null; //连接数据库
ResultSet rs = null;
Statement stmt = null;
private static stuBean1 me=new stuBean1();
public stuBean1 () {
}
public static stuBean1 newInstance(){
return me;
}
public Connection getConnDB(){
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newInstance() ;
con=DriverManager.getConnection("jdbc:odbc:studb"); //连接数据源
} catch (Exception ex) {
ex.printStackTrace();
}
return con;
}
}
列界数据库的类.然后建个文件存放增删改查的超做。
下面是增加数据库的代码:
package student;
import java.sql.*;
public class stuBean1{
Connection con = null; //连接数据库
ResultSet rs = null;
Statement stmt = null;
private static stuBean1 me=new stuBean1();
public stuBean1 () {
}
public static stuBean1 newInstance(){
return me;
}
public Connection getConnDB(){
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newInstance() ;
con=DriverManager.getConnection("jdbc:odbc:studb"); //连接数据源
} catch (Exception ex) {
ex.printStackTrace();
}
return con;
}
}
然后在在servlet文件里传值
package student;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
public class Servlet extends HttpServlet {
private static final String CONTENT_TYPE = "text/html; charset=GBK";
//Initialize global variables
public void init() throws ServletException {
}
//Process the HTTP Get request
public void doGet(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter(); //从文本框中获取值
response.setCharacterEncoding("GB2312");
String loginName=request.getParameter("loginName");
String password=request.getParameter("password");
String truename=request.getParameter("truename");
String semester=request.getParameter("term");
semester = semester.trim();
System.out.println(semester);
studentBean1 bean=new studentBean1();
bean.setLoginName(loginName);
bean.setPassword(password);
bean.setTrurname(truename);
bean.setSemester(semester);
insert bean1=new insert();
int result=0;
result=bean1.getinsert(bean); //调用方法做增加数据
if (result>0)
{
request.getRequestDispatcher("rightmain.jsp").forward(request,response);
}
else
{
request.getRequestDispatcher("error.jsp").forward(request,response);
}
out.close();
}
//Process the HTTP Post request
public void doPost(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
doGet(request, response);
}
//Clean up resources
public void destroy() {
}
}
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