String str="select * from tb_user_lt where username='"+username+"'";
ResultSet rs=stmt.executeQuery(str);
if(!rs.next())
{
try
{
//通过预处理对象向数据库中添加记录
PreparedStatement pstmt=con.prepareStatement("insert into tb_user_lt(username,password,nicheng) values(?,?,?)");
pstmt.setString(1,username);
pstmt.setString(2,password1);
pstmt.setString(3,nicheng);
pstmt.executeUpdate();
//String str1="insert into tb_user_lt(username,password,nicheng) values";
//str1=str1+"("+username+","+password1+"'"+nicheng+")";
//ResultSet rs1=stmt.executeQuery(str1);
}
catch(Exception e)
{
e.printStackTrace();
}
out.println("<script language='javascript'>alert('注册成功!');parent.location.href='login.html';</script>");
rs.close();
stmt.close();
con.close();代码如上所示,运行结果也显示了“注册成功!”,但在数据库中并没有看到添加的记录,这是怎么回事?
ResultSet rs=stmt.executeQuery(str);
if(!rs.next())
{
try
{
//通过预处理对象向数据库中添加记录
PreparedStatement pstmt=con.prepareStatement("insert into tb_user_lt(username,password,nicheng) values(?,?,?)");
pstmt.setString(1,username);
pstmt.setString(2,password1);
pstmt.setString(3,nicheng);
pstmt.executeUpdate();
//String str1="insert into tb_user_lt(username,password,nicheng) values";
//str1=str1+"("+username+","+password1+"'"+nicheng+")";
//ResultSet rs1=stmt.executeQuery(str1);
}
catch(Exception e)
{
e.printStackTrace();
}
out.println("<script language='javascript'>alert('注册成功!');parent.location.href='login.html';</script>");
rs.close();
stmt.close();
con.close();代码如上所示,运行结果也显示了“注册成功!”,但在数据库中并没有看到添加的记录,这是怎么回事?
{
out.println(e.getLocalizedMessage()); //看看是否报错了
}
还有就是刷新数据库看记录是否存在