Question

asp+sql如何在多表联合查询中，重复的记录只输出一条

数据表x字段如下
ID oderid
4 123
3 123
2 123
1 123
数据表y字段如下
4 123
<%sql="select x.ID,x.orderid,y.ID from x,y where x.orderid=y.orderid"
rs.open sql,conn,1,1%>
do while not rs.eof
<%=rs(1)%><br>
rs.movenext
loop
输出结果为
123
123
123
123
正确输出结果应该是
123
求高手解答！！！！！！！！！！~！~！~！~！~

Answer 1

sql="select x.ID,x.orderid,y.ID from x,y where id in (select min(id) from x,y group by oderid) and x.orderid=y.orderid"

Answer 2

为了新手任务

Answer 3

distinct