<%@page contentType="text/html;charset=GB2312"%>
<%@ include file="share/connection.jsp"%>
<html>
<body>
<%
String name=request.getParameter("name");
if(name==null){
name="";
} byte b[]=name.getBytes("ISO-8859-1");
name=new String(b);
out.print(name);
String xuefen=request.getParameter("xuefen");
if(xuefen==null){ xuefen="-1";
}
out.print(xuefen);
//更新数据************************************
String sql = "update stu set credit=' "+xuefen+"'"+" where stuname=' "+name+"'";
try{
stmt.executeUpdate(sql);
}catch(SQLException e){
out.print(e);
}
%>
<center><p>更新后数据库的记录:
<%
ResultSet rs=stmt.executeQuery("select * from stu");
%>
</p>
<table boder="" bgcolor="green">
<tbody>
<tr>
<th width="100">学号</th>
<th width="100">姓名</th>
<th width="50">学分</th>
</tr>
<%while(rs.next()){%>
<tr><td><%=rs.getInt(1)%></td>
<td><%=rs.getString(2)%></td>
<td><%=rs.getString(3)%></td>
</tr>
<%
}
%>
</tbody></center><%
conn.close();
%>
</body></html>
为什么我的更新语句起不了作用,显示结果还是更改前的数据. who can help me?????????????????????????????????????????
<%@ include file="share/connection.jsp"%>
<html>
<body>
<%
String name=request.getParameter("name");
if(name==null){
name="";
} byte b[]=name.getBytes("ISO-8859-1");
name=new String(b);
out.print(name);
String xuefen=request.getParameter("xuefen");
if(xuefen==null){ xuefen="-1";
}
out.print(xuefen);
//更新数据************************************
String sql = "update stu set credit=' "+xuefen+"'"+" where stuname=' "+name+"'";
try{
stmt.executeUpdate(sql);
}catch(SQLException e){
out.print(e);
}
%>
<center><p>更新后数据库的记录:
<%
ResultSet rs=stmt.executeQuery("select * from stu");
%>
</p>
<table boder="" bgcolor="green">
<tbody>
<tr>
<th width="100">学号</th>
<th width="100">姓名</th>
<th width="50">学分</th>
</tr>
<%while(rs.next()){%>
<tr><td><%=rs.getInt(1)%></td>
<td><%=rs.getString(2)%></td>
<td><%=rs.getString(3)%></td>
</tr>
<%
}
%>
</tbody></center><%
conn.close();
%>
</body></html>
为什么我的更新语句起不了作用,显示结果还是更改前的数据. who can help me?????????????????????????????????????????
把那个SQL语句打出来,在命令行里测试一下看看。
有几个原因导致不符合你的预期。
1.字符集问题
2.碰到转义字符 ', "等等