Rst=Stmt.executeQuery("select top 10 * from table order by ....");
不知道为什么,我用select * from shade, 就好用,而用 是select top 3 from shade 就不好用呢出现以下错误 : null java.lang.NullPointerException at jrun__wangzhan__shade2ejsp13._jspService(jrun__wangzhan__shade2ejsp13.java:72) at allaire.jrun.jsp.HttpJSPServlet.service(HttpJSPServlet.java:40) at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1013) at allaire.jrun.servlet.JRunSE.runServlet(JRunSE.java:925) at allaire.jrun.servlet.JRunNamedDispatcher.forward(JRunNamedDispatcher.java:34) at allaire.jrun.jsp.JSPServlet.service(JSPServlet.java:174) at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1013) at allaire.jrun.servlet.JRunSE.runServlet(JRunSE.java:925) at allaire.jrun.servlet.JRunRequestDispatcher.forward(JRunRequestDispatcher.java:88) at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1131) at allaire.jrun.servlet.JvmContext.dispatch(JvmContext.java:330) at allaire.jrun.http.WebEndpoint.run(WebEndpoint.java:107) at allaire.jrun.ThreadPool.run(ThreadPool.java:267) at allaire.jrun.WorkerThread.run(WorkerThread.java:74) 大虾请指教!
select top 3 from shade ?你没有指出select top 3 什么(这里要加字段名的)比如name......就是说你想得到前三个什么呀?我写的top 3 * 是获得所有字段
java.util.Date currentTime_1 = new java.util.Date(); 后边加上 currentTime=formatter.format(currentTime_1);
不行啊。最长的代码我也用过了出现如下差错:javax.servlet.ServletException: Compilation error occured: Found 1 errors in JSP file: D:\\JRun\\servers\\default\\default-app\\wangzhan\\DO_SHADE.JSP:29: Error: No match was found for constructor "Date()".我该怎么办?
是select top 3 from shade 就不好用呢出现以下错误 :
null
java.lang.NullPointerException
at jrun__wangzhan__shade2ejsp13._jspService(jrun__wangzhan__shade2ejsp13.java:72)
at allaire.jrun.jsp.HttpJSPServlet.service(HttpJSPServlet.java:40)
at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1013)
at allaire.jrun.servlet.JRunSE.runServlet(JRunSE.java:925)
at allaire.jrun.servlet.JRunNamedDispatcher.forward(JRunNamedDispatcher.java:34)
at allaire.jrun.jsp.JSPServlet.service(JSPServlet.java:174)
at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1013)
at allaire.jrun.servlet.JRunSE.runServlet(JRunSE.java:925)
at allaire.jrun.servlet.JRunRequestDispatcher.forward(JRunRequestDispatcher.java:88)
at allaire.jrun.servlet.JRunSE.service(JRunSE.java:1131)
at allaire.jrun.servlet.JvmContext.dispatch(JvmContext.java:330)
at allaire.jrun.http.WebEndpoint.run(WebEndpoint.java:107)
at allaire.jrun.ThreadPool.run(ThreadPool.java:267)
at allaire.jrun.WorkerThread.run(WorkerThread.java:74)
大虾请指教!
比如:select top 10 * from mytable如果想把表中最近插入的20各纪录找出来,可以为这个表设一个date类型的字段,然后把默认值设为getdate(),这样一条新纪录添加的时候就会自动记录日期,然后通过这个日期查询。明白了吗?
int year=now_time.getYear()+1900;
int monthi=now_time.getMonth()+1;
String month="";
if(monthi<10)month="0"+monthi;
else month=""+monthi;
int dayi=now_time.getDate();
String day="";
if(dayi<10)day="0"+dayi;
else day=""+dayi;
int houri=now_time.getHours();
String hour="";
if(houri<10)hour="0"+houri;
else hour=""+houri;
int minutei=now_time.getMinutes();
String minute="";
if(minutei<10)minute="0"+minutei;
else minute=""+minutei;
int secondi=now_time.getSeconds();
String second="";
if(secondi<10)second="0"+secondi;
else second=""+secondi;
String time=year+"-"+month+"-"+day+" "+hour+":"+minute+":"+second;然后吧time写入一个vrchar的字段time里
赶快结,不然我的方法被人骂死了,丢人呀...........
java.text.SimpleDateFormat formatter = new java.text.SimpleDateFormat("yyyy/MM/dd HH/mm/ss");
java.util.Date currentTime_1 = new java.util.Date();
out.print(formatter.format(currentTime_1));
%>运行结果:
2001/07/31 10/32/52有高手指点!!!他刚告诉我的
java.util.Date now=new java.util.Date();
java.text.SimpleDateFormat formatter = new java.text.SimpleDateFormat("yyyy/MM/dd HH/mm/ss");
java.util.Date currentTime_1 = new java.util.Date();
String strSQL="insert into shade values('" + name1 + "','" + shade1 + "','"+currentTime_1 "')";
你看看问题出在那?
后边加上
currentTime=formatter.format(currentTime_1);
Found 1 errors in JSP file:
D:\\JRun\\servers\\default\\default-app\\wangzhan\\DO_SHADE.JSP:29: Error: No match was found for constructor "Date()".我该怎么办?
这个你只能先读出上边的放再表格里,然后再查询一次找到最新的现实再最下边如果你希望上边的(最近20条不包括最新的一条,你不是要放再最下边么)你再读数据库的时候应该有while(rst.next()){ }语句循环取数据
别告诉我你没有你可以在while(rst.next()){}之前先rst.next(); 跳过最新的一条这样实现最近20条不包括最新的一条,最新的一条在最下边