sql数据库聚集索引和非聚集索引示例
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责编:小采
时间:2020-11-09 10:04:10
sql数据库聚集索引和非聚集索引示例
sql数据库聚集索引和非聚集索引示例: create database myIndexDemogouse myIndexDemogocreate table ABC(A int not null,B char(10),C varchar(10))goinsert into ABCselect 1,'B','C'unionselect 5,'B','C'unionselect 7,'B','C'unionselect 9,'B','C'go select * from ABC --在ABC表上创建聚集索引cr
导读sql数据库聚集索引和非聚集索引示例: create database myIndexDemogouse myIndexDemogocreate table ABC(A int not null,B char(10),C varchar(10))goinsert into ABCselect 1,'B','C'unionselect 5,'B','C'unionselect 7,'B','C'unionselect 9,'B','C'go select * from ABC --在ABC表上创建聚集索引cr

create database myIndexDemo go use myIndexDemo go create table ABC ( A int not null, B char(10), C varchar(10) ) go insert into ABC select 1,'B','C' union select 5,'B','C' union select 7,'B','C' union select 9,'B','C' go
select * from ABC
--在ABC表上创建聚集索引 create clustered index CLU_ABC on ABC(A)
--查看索引 sp_helpIndex abc
--插入数据 insert into ABC values(2,'B','C')
--因为有聚集索引所以整个表的物理结构发生了变化 --此时按照该索引查询的内容为: select * from ABC (index = NONCLU_ABC)
--删除索引后 Drop index ABC.CLU_ABC
--查询内容物理顺序还是按照顺序的 select * from ABC
--在ABC表上创建非聚集索引 create nonclustered index NONCLU_ABC on ABC(A)
--查看索引 sp_helpIndex abc
--插入数据 insert into ABC values(4,'B','C')
--因为有聚集索引所以整个表的物理结构发生了变化 --此时查询的内容为: select * from ABC (index = NONCLU_ABC)
--删除索引后 Drop index ABC.NONCLU_ABC
--查询内容物理顺序是按照插入的顺序 select * from ABC
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sql数据库聚集索引和非聚集索引示例
sql数据库聚集索引和非聚集索引示例: create database myIndexDemogouse myIndexDemogocreate table ABC(A int not null,B char(10),C varchar(10))goinsert into ABCselect 1,'B','C'unionselect 5,'B','C'unionselect 7,'B','C'unionselect 9,'B','C'go select * from ABC --在ABC表上创建聚集索引cr