帮我看下这句问题出在哪里呢？？？？

有这么一句：

sqlstr="select * from board where ban="&request.QueryString("id")
这样写就没问题！！！

sqlstr="select * from board where ban="&request.QueryString("id")&"order by id desc"
这样写就有问题，请问我如何改下才正确呀？？？？？？？？？？？？？？谢谢
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sqlstr="select * from board where ban="&request.QueryString("id")&" order by id desc"

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sqlstr="select * from board where ban="&request.QueryString("id")&" order by id desc"
" order by id desc"第一个字符空格