create table T(A int, B int) insert T select 1, 2 insert T select 32, 22 insert T select 10, 12select *, MaxValue=( select max(A) from (select tmp.A union all select tmp.B) tmpMax) from T as tmp--result A B MaxValue ----------- ----------- ----------- 1 2 2 32 22 32 10 12 12(3 row(s) affected)
借用楼上的数据:create table T(A int, B int) insert T select 1, 2 insert T select 32, 22 insert T select 10, 12SELECT * FROM TSELECT A, B, CASE WHEN A>=B THEN A ELSE B END AS MAXVALUE FROM TDROP TABLE T
insert T select 1, 2
insert T select 32, 22
insert T select 10, 12select *,
MaxValue=( select max(A) from (select tmp.A union all select tmp.B) tmpMax)
from T as tmp--result
A B MaxValue
----------- ----------- -----------
1 2 2
32 22 32
10 12 12(3 row(s) affected)
insert T select 1, 2
insert T select 32, 22
insert T select 10, 12SELECT * FROM TSELECT
A,
B,
CASE WHEN A>=B THEN A ELSE B END AS MAXVALUE
FROM TDROP TABLE T
以后要建表T时再删除