diff --git a/DB/exp1.sql b/DB/exp1.sql
index 55e8154..e06efff 100644
--- a/DB/exp1.sql
+++ b/DB/exp1.sql
@@ -19,7 +19,8 @@ create table orders(
        m_account varchar(20) references members(m_account),
        p_no char(10) references products(p_no),
        o_quantity int,
-       o_date date
+       o_date date,
+	   primary key (m_account,p_no)
        );
 
 insert into members values ('jin', '刘津', '女', '北京', 8200, 'jin'),