我是SQL新手,我試圖在兩個REF'd列值之間獲取2個值之間的日期。 我現在有表設置如下圖所示: CREATE OR REPLACE TYPE Person_Type AS OBJECT
(PersonId NUMBER,
DateBorn DATE)
CREATE OR REPLACE TYPE Movie_Type AS OBJECT
(MovieId NUMBER,
Releas
/*Tables:*/
SELECT tid, SID FROM t_s_map;/*student id whom teacher has access*/
SELECT sgid FROM sg;/* student_group table*/
SELECT sgid, SID FROM sgm;/*student group members table(info of students