日期:2014-05-18 浏览次数:20753 次
--索引资料
drop table index_tb
create table index_tb(id int constraint ck_id default 0,name varchar(20),xb varchar(2))
--查看表
exec sp_helpconstraint index_tb
--键不唯一,非聚集索引
create index id_index on index_tb(id)
--删除索引
drop index index_tb.id_index
--键聚集索引
create clustered index id_index on index_tb(id)
--删除索引
drop index index_tb.id_index
--创建check约束
alter table index_tb add constraint ck_index CHECK (name like '[0-9][0-9][0-9][0-9][0-9]')
alter table index_tb add constraint ck2_index check(xb in ('MM','GG'))
--删除check约束
alter table index_tb drop constraint ck2_index
--禁止表约束
alter table index_tb nocheck constraint ck_index
--恢复表约束
alter table index_tb check constraint ck_index
--禁止和恢复所有check-all关键字
select 'alter table '+name+' nocheck or check constraint all' from sysobjects where type='U'
--添加新默认值和约束
ALTER TABLE index_tb ADD CONSTRAINT de_name DEFAULT ('11111') FOR name
--删除表约束
alter table index_tb drop constraint de_name
-- 字段 UNIQUE NOT NULL = PRIMARY KEY 差不多
insert into index_tb(name,xb) select '12345','mm'
select * from index_tb
delete index_tb
------解决方案--------------------
NewsList.NewsTypeid 建 NONCLUSTERED 索引
NewsType.Newstypeid 建 Unique CLUSTERED索引
------解决方案--------------------
create clustered index id_index1 on NewList(NewsTypeid) go create index id_index2 on NewsType(Newstypeid) go Select Articletitle,ArticleUrl,TypeName,NewsDate From NewsList,NewsType where NewsList.NewsTypeid=NewsType.Newstypeid
------解决方案--------------------
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