sqlÇóÒ»ÁеÄƽ¾ùÖµ

¼ÙÉè ÓÐÒ»¸öѧÉú±í
ÒѼÈë ³É¼¨1 ³É¼¨2 ³É¼¨3
ÏÖÔÚÏëÔö¼ÓÒ»ÁÐƽ¾ù·Ö
ÇëÎÊÓÐʲô°ì·¨ÄÜ×Ô¶¯ÌîÈëƽ¾ù·ÖÕâÏîµÄÖµ

---

SQL code:

alter table ѧÉú±í add ƽ¾ù·Ö as ((³É¼¨1+³É¼¨2+³É¼¨3)/3)

---

select *,ƽ¾ù·Ö =(³É¼¨1+³É¼¨2+³É¼¨3)/3
from ta

---

.

---

SQL code:
--Ð޸ıí½á¹¹
alter table ѧÉú±í add ƽ¾ù·Ö as ((³É¼¨1+³É¼¨2+³É¼¨3)*1.0/3)--Ë®¸çµÄ
--Ö±½Ó²éѯ
select *,ƽ¾ù·Ö =(³É¼¨1+³É¼¨2+³É¼¨3)*1.0/3
from ta
--ʯͷ¸ç

---

ÒýÓÃ

alter table ѧÉú±í add ƽ¾ù·Ö as ((³É¼¨1+³É¼¨2+³É¼¨3)/3)

alter table ѧÉú±í add ƽ¾ù·Ö as ((³É¼¨1+³É¼¨2+³É¼¨3)/3.0)
go

---

SQL code:

alter table ѧÉú±í add ƽ¾ù·Ö as ((³É¼¨1+³É¼¨2+³É¼¨3)/3.00)

---

alter table ±íÃû add ƽ¾ù·Ö as ((³É¼¨1+³É¼¨2+³É¼¨3)/3.0)
go