sql数据库怎么把默认值设置为两个字段相减 sql数据库怎么把默认值设置为两个字段相减比如table中三个字段 a b cc的值怎么设置默认为(a-b)?求大神指教!sql.net 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 create table [dbo].[table_name] ( [a] [int] null, [b] [int] null, [col_add] as ([a]+[b]), [col_ji] as ([a]*[b]) ) on [primary] --插入数据insert into table_name(a,b)select 2,3 --查询出结果select * from table_name --删掉表drop table table_name /*a b col_add col_ji----------- ----------- ----------- -----------2 3 5 6*/ --如果关系是固定可以用类似#1的形式。create table [dbo].[table_test] ( [a] [int] null, [b] [int] null, [c] as ([a]-[b]) )insert into [table_test](a,b) select 10,6 select * from [table_test]/*a b c----------- ----------- -----------10 6 4*/--正常情况不用存,取得的时候计算一下就可以了。select a,b,a-b as c from tablename CREATE TABLE test( a INT, b INT, c AS a-b)INSERT INTO test(a,b)VALUES (2,1)SELECT * FROM test/*a b c----------- ----------- -----------2 1 1*/ 为啥要用视图?如果非要用视图,假设你的表只有a、b列create view testasselect a,b,a-b as cfrom test 索引问题 查询字段KKK为空,KKK=''和kkk is null有什么区别? 一张表的image类型字段更新到另一张表的image类型字段,sql 怎么写? 求更新表内记录的sql语句写法 如何让空数据列显示为“0” 如何按一定数据分组 SQL执行时间太长 如何定义一个连接内可用的变量? 多条记录的存储和信息推送功能实现 求围观~~~! 两网卡的服务器,查询分析器连接sql server 2000报错:SQL Server不存在或访问被拒绝? 表复制数据的sql语句问题,求高手!!!! VS2012数据库SQL出现乱码?
create table [dbo].[table_name]
(
[a] [int] null,
[b] [int] null,
[col_add] as ([a]+[b]),
[col_ji] as ([a]*[b])
)
on [primary]
--插入数据
insert into table_name(a,b)
select 2,3
--查询出结果
select * from table_name
--删掉表
drop table table_name
/*
a b col_add col_ji
----------- ----------- ----------- -----------
2 3 5 6
*/
create table [dbo].[table_test]
(
[a] [int] null,
[b] [int] null,
[c] as ([a]-[b])
)
insert into [table_test](a,b)
select 10,6
select * from [table_test]
/*
a b c
----------- ----------- -----------
10 6 4
*/--正常情况不用存,取得的时候计算一下就可以了。select a,b,a-b as c from tablename
(
a INT,
b INT,
c AS a-b
)INSERT INTO test(a,b)
VALUES (2,1)SELECT * FROM test/*
a b c
----------- ----------- -----------
2 1 1
*/
create view test
as
select a,b,a-b as c
from test