VBScript code: conn.execute("SET IDENTITY_INSERT [abc] On" & vbcrlf & "insert into [abc] (id,name,qq,msn) select (select top 1 id from [abc] order by id desc)+1,name,qq,msn) from [abc] where id="&sid&" & vbcrlf & "SET IDENTITY_Insert [abc] OFF")
这样可以复制新的一行，但是如果有很多用户同时使用，如果并发的话，这里面的select top 1肯定就不对了？
select id,name,type from A union all select id,name,type from B union all select id,name,type from C union all where ??? ---------------------------------------------------- ......
