sqlserver中一些常用的查询语句

sqlserver 实现分页查询

select top ("+pageSize+") word from(select distinct(d_word)as word,row_number() over(order by id asc) as rownumber from dbo.zdbz_dict_all) as tb where rownumber>("+(i*pageSize)+") 

 

将查询出来的数据导入到另外一个表中

 

insert into test_cs(word)

select distinct(d_word) as word from dbo.zdbz_dict_all 

 

创建表

use yike_test

create table zdbz_nky_phrase_nlp(

id int PRIMARY KEY IDENTITY(1,1),

sid nvarchar(4000),

title nvarchar(4000),

keyword nvarchar(4000),

abstract nvarchar(4000),

phrase nvarchar(4000),

startpos int,

endpos int

)

mysql中的去重语句

delete disease as a from disease as a,

 (

 select * from disease group by name having count(1)>1) as b

where a.name=b.name and a.id > b.id;

） 

 sqlserver中查询字符串中含有%

select * from dbo.test_cs where word like '%%c%%' escape 'c'

 

select * from dbo.zdbz_dict_all where t_word like '%[%]%'

表示字符串中含有%就行

 

select * from dbo.test_cs where word like '%c%' escape 'c'

查询的结果为所有以%结尾的数据

select * from dbo.test_cs where word like 'e%%' escape 'e'

查询的结果为所有以%开始的数据

 sql语句实现数据库中的两个表数据之间的更新

 

 

update dbo.zdbz_dict_all set origin=b.word from dbo.zdbz_dict_all as a
,dbo.origin as b where a.id=b.uri

 

基于数据库表建立索引

 

CREATE NONCLUSTERED INDEX IX_origin --创建一个非聚集索引
ON dbo.zdbz_dict_all(origin)  --为dbo.zdbz_dict_all表的origin字段创建索引
WITH FILLFACTOR = 30 --填充因子为30%

 

 

 

如果将set statistics io 设置为on,则在执行SQL语句时将会显示磁盘活动的统计信息。如果将set statistics
io设置为off,则不显示统计信息。

 

set statistics io on
select * from
stuinfo--执行语句
set statistics
io off

 基于SQLServer性能测试

 

create table table1
(
    ID int identity(1,1),
    UserID int,
    OtherCol1 varchar(300),
    OtherCol2 varchar(300)
)
create clustered index index_id on table1(id)
 
 
--清理一下表
truncate table table1
declare @i int
set @i=1
while (@i<2000000)
begin
    insert into table1 values(substring(cast( RAND() as varchar),3,3),CAST(@i as varchar),CAST(@i as varchar));
    set @i=@i+1
end
select count(1)from dbo.table1
select GETDATE()
select * from table1 where UserID='666'
create  index index_userid on table1(userid)
select GETDATE()
drop index index_userid on table1

 

 

 

转载于:https://www.cnblogs.com/hxy520/archive/2013/02/01/2889384.html