表单有多个条件输入或选择，如果表单某项为空则不查询这个项，语句怎么写，谢谢。

举例:
sql = "select [id],[title] from [table]"
if reauest.form("key")<>"" then sql = sql " whrer [title] like '%" & reauest.form("key") & "%'"
sql = sql & " order by [id] desc"

sql = "select [id],[title] from [table] where 1=1"
if reauest.form("key")<>"" then sql = sql & " and [title] like '%" & reauest.form("key") & "%'"
sql = sql & " order by [id] desc"