T-SQL經(jīng)典語(yǔ)句 送給需要的人
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一、基礎(chǔ)

1、說(shuō)明:創(chuàng)建數(shù)據(jù)庫(kù)

CREATE DATABASE database-name

2、說(shuō)明:刪除數(shù)據(jù)庫(kù)

drop database dbname

3、說(shuō)明:備份sql server

--- 創(chuàng)建 備份數(shù)據(jù)的 device

USE master

EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat'

--- 開(kāi)始 備份

BACKUP DATABASE pubs TO testBack

4、說(shuō)明:創(chuàng)建新表

create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)

根據(jù)已有的表創(chuàng)建新表:

A:create table tab_new like tab_old (使用舊表創(chuàng)建新表)

B:create table tab_new as select col1,col2… from tab_old definition only

5、說(shuō)明:刪除新表

drop table tabname

6、說(shuō)明:增加一個(gè)列

Alter table tabname add column col type

注:列增加后將不能刪除。DB2中列加上后數(shù)據(jù)類(lèi)型也不能改變,唯一能改變的是增加varchar類(lèi)型的長(zhǎng)度。

7、說(shuō)明:添加主鍵: Alter table tabname add primary key(col)

說(shuō)明:刪除主鍵: Alter table tabname drop primary key(col)

8、說(shuō)明:創(chuàng)建索引:create [unique] index idxname on tabname(col….)

刪除索引:drop index idxname

注:索引是不可更改的,想更改必須刪除重新建。

9、說(shuō)明:創(chuàng)建視圖:create view viewname as select statement

刪除視圖:drop view viewname

10、說(shuō)明:幾個(gè)簡(jiǎn)單的基本的sql語(yǔ)句

選擇:select * from table1 where 范圍

插入:insert into table1(field1,field2) values(value1,value2)

刪除:delete from table1 where 范圍

更新:update table1 set field1=value1 where 范圍

查找:select * from table1 where field1 like ’%value1%’ ---like的語(yǔ)法很精妙,查資料!

排序:select * from table1 order by field1,field2 [desc]

總數(shù):select count as totalcount from table1

求和:select sum(field1) as sumvalue from table1

平均:select avg(field1) as avgvalue from table1

最大:select max(field1) as maxvalue from table1

最小:select min(field1) as minvalue from table1

11、說(shuō)明:幾個(gè)高級(jí)查詢(xún)運(yùn)算詞

A: UNION 運(yùn)算符

UNION 運(yùn)算符通過(guò)組合其他兩個(gè)結(jié)果表(例如 TABLE1 和 TABLE2)并消去表中任何重復(fù)行而派生出一個(gè)結(jié)果表。當(dāng) ALL 隨 UNION 一起使用時(shí)(即 UNION ALL),不消除重復(fù)行。兩種情況下,派生表的每一行不是來(lái)自 TABLE1 就是來(lái)自 TABLE2。

B: EXCEPT 運(yùn)算符

EXCEPT 運(yùn)算符通過(guò)包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重復(fù)行而派生出一個(gè)結(jié)果表。當(dāng) ALL 隨 EXCEPT 一起使用時(shí) (EXCEPT ALL),不消除重復(fù)行。

C: INTERSECT 運(yùn)算符

INTERSECT 運(yùn)算符通過(guò)只包括 TABLE1 和 TABLE2 中都有的行并消除所有重復(fù)行而派生出一個(gè)結(jié)果表。當(dāng) ALL 隨 INTERSECT 一起使用時(shí) (INTERSECT ALL),不消除重復(fù)行。

注:使用運(yùn)算詞的幾個(gè)查詢(xún)結(jié)果行必須是一致的。

12、說(shuō)明:使用外連接

A、left outer join:

左外連接(左連接):結(jié)果集幾包括連接表的匹配行,也包括左連接表的所有行。

SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c

B:right outer join:

右外連接(右連接):結(jié)果集既包括連接表的匹配連接行,也包括右連接表的所有行。

C:full outer join:

全外連接:不僅包括符號(hào)連接表的匹配行,還包括兩個(gè)連接表中的所有記錄。

二、提升

1、說(shuō)明:復(fù)制表(只復(fù)制結(jié)構(gòu),源表名:a 新表名:b) (Access可用)

法一:select * into b from a where 1<>1

法二:select top 0 * into b from a

2、說(shuō)明:拷貝表(拷貝數(shù)據(jù),源表名:a 目標(biāo)表名:b) (Access可用)

insert into b(a, b, c) select d,e,f from b;

3、說(shuō)明:跨數(shù)據(jù)庫(kù)之間表的拷貝(具體數(shù)據(jù)使用絕對(duì)路徑) (Access可用)

insert into b(a, b, c) select d,e,f from b in ‘具體數(shù)據(jù)庫(kù)’ where 條件

例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where..

4、說(shuō)明:子查詢(xún)(表名1:a 表名2:b)

select a,b,c from a where a IN (select d from b ) 或者: select a,b,c from a where a IN (1,2,3)

5、說(shuō)明:顯示文章、提交人和最后回復(fù)時(shí)間

select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b

6、說(shuō)明:外連接查詢(xún)(表名1:a 表名2:b)

select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c

7、說(shuō)明:在線視圖查詢(xún)(表名1:a )

select * from (SELECT a,b,c FROM a) T where t.a > 1;

8、說(shuō)明:between的用法,between限制查詢(xún)數(shù)據(jù)范圍時(shí)包括了邊界值,not between不包括

select * from table1 where time between time1 and time2

select a,b,c, from table1 where a not between 數(shù)值1 and 數(shù)值2

9、說(shuō)明:in 的使用方法

select * from table1 where a [not] in (‘值1’,’值2’,’值4’,’值6’)

10、說(shuō)明:兩張關(guān)聯(lián)表,刪除主表中已經(jīng)在副表中沒(méi)有的信息

delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 )

11、說(shuō)明:四表聯(lián)查問(wèn)題:

select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where .....

12、說(shuō)明:日程安排提前五分鐘提醒

SQL: select * from 日程安排 where datediff('minute',f開(kāi)始時(shí)間,getdate())>5

13、說(shuō)明:一條sql 語(yǔ)句搞定數(shù)據(jù)庫(kù)分頁(yè)

select top 10 b.* from (select top 20 主鍵字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主鍵字段 = a.主鍵字段 order by a.排序字段

14、說(shuō)明:前10條記錄

select top 10 * form table1 where 范圍

15、說(shuō)明:選擇在每一組b值相同的數(shù)據(jù)中對(duì)應(yīng)的a最大的記錄的所有信息(類(lèi)似這樣的用法可以用于論壇每月排行榜,每月熱銷(xiāo)產(chǎn)品分析,按科目成績(jī)排名,等等.)

select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b)

16、說(shuō)明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重復(fù)行而派生出一個(gè)結(jié)果表

(select a from tableA ) except (select a from tableB) except (select a from tableC)

17、說(shuō)明:隨機(jī)取出10條數(shù)據(jù)

select top 10 * from tablename order by newid()

18、說(shuō)明:隨機(jī)選擇記錄

select newid()

19、說(shuō)明:刪除重復(fù)記錄

Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...)

20、說(shuō)明:列出數(shù)據(jù)庫(kù)里所有的表名

select name from sysobjects where type='U'

21、說(shuō)明:列出表里的所有的

select name from syscolumns where id=object_id('TableName')

22、說(shuō)明:列示type、vender、pcs字段,以type字段排列,case可以方便地實(shí)現(xiàn)多重選擇,類(lèi)似select 中的case。

select type,sum(case vender when 'A' then pcs else 0 end),sum(case vender when 'C' then pcs else 0 end),sum(case vender when 'B' then pcs else 0 end) FROM tablename group by type

顯示結(jié)果:

type vender pcs

電腦 A 1

電腦 A 1

光盤(pán) B 2

光盤(pán) A 2

手機(jī) B 3

手機(jī) C 3

23、說(shuō)明:初始化表table1

TRUNCATE TABLE table1

24、說(shuō)明:選擇從10到15的記錄

select top 5 * from (select top 15 * from table order by id asc) table_別名 order by id desc

三、技巧

1、1=1,1=2的使用,在SQL語(yǔ)句組合時(shí)用的較多

“where 1=1” 是表示選擇全部 “where 1=2”全部不選,

如:

if @strWhere !=''

begin

set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere

end

else

begin

set @strSQL = 'select count(*) as Total from [' + @tblName + ']'

end

我們可以直接寫(xiě)成

set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere

2、收縮數(shù)據(jù)庫(kù)

--重建索引

DBCC REINDEX

DBCC INDEXDEFRAG

--收縮數(shù)據(jù)和日志

DBCC SHRINKDB

DBCC SHRINKFILE

3、壓縮數(shù)據(jù)庫(kù)

dbcc shrinkdatabase(dbname)

4、轉(zhuǎn)移數(shù)據(jù)庫(kù)給新用戶(hù)以已存在用戶(hù)權(quán)限

exec sp_change_users_login 'update_one','newname','oldname'

go

5、檢查備份集

RESTORE VERIFYONLY from disk='E:\dvbbs.bak'

6、修復(fù)數(shù)據(jù)庫(kù)

ALTER DATABASE [dvbbs] SET SINGLE_USER

GO

DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK

GO

ALTER DATABASE [dvbbs] SET MULTI_USER

GO

7、日志清除

SET NOCOUNT ON

DECLARE @LogicalFileName sysname,

@MaxMinutes INT,

@NewSize INT

USE tablename -- 要操作的數(shù)據(jù)庫(kù)名

SELECT @LogicalFileName = 'tablename_log', -- 日志文件名

@MaxMinutes = 10, -- Limit on time allowed to wrap log.

@NewSize = 1 -- 你想設(shè)定的日志文件的大小(M)

-- Setup / initialize

DECLARE @OriginalSize int

SELECT @OriginalSize = size

FROM sysfiles

WHERE name = @LogicalFileName

SELECT 'Original Size of ' + db_name() + ' LOG is ' +

CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' +

CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB'

FROM sysfiles

WHERE name = @LogicalFileName

CREATE TABLE DummyTrans

(DummyColumn char (8000) not null)

DECLARE @Counter INT,

@StartTime DATETIME,

@TruncLog VARCHAR(255)

SELECT @StartTime = GETDATE(),

@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY'

DBCC SHRINKFILE (@LogicalFileName, @NewSize)

EXEC (@TruncLog)

-- Wrap the log if necessary.

WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired

AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName)

AND (@OriginalSize * 8 /1024) > @NewSize

BEGIN -- Outer loop.

SELECT @Counter = 0

WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000))

BEGIN -- update

INSERT DummyTrans VALUES ('Fill Log')

DELETE DummyTrans

SELECT @Counter = @Counter + 1

END

EXEC (@TruncLog)

END

SELECT 'Final Size of ' + db_name() + ' LOG is ' +

CONVERT(VARCHAR(30),size) + ' 8K pages or ' +

CONVERT(VARCHAR(30),(size*8/1024)) + 'MB'

FROM sysfiles

WHERE name = @LogicalFileName

DROP TABLE DummyTrans

SET NOCOUNT OFF

8、說(shuō)明:更改某個(gè)表

exec sp_changeobjectowner 'tablename','dbo'

9、存儲(chǔ)更改全部表

CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch

@OldOwner as NVARCHAR(128),

@NewOwner as NVARCHAR(128)

AS

DECLARE @Name as NVARCHAR(128)

DECLARE @Owner as NVARCHAR(128)

DECLARE @OwnerName as NVARCHAR(128)

DECLARE curObject CURSOR FOR

select 'Name' = name,

'Owner' = user_name(uid)

from sysobjects

where user_name(uid)=@OldOwner

order by name

OPEN curObject

FETCH NEXT FROM curObject INTO @Name, @Owner

WHILE(@@FETCH_STATUS=0)

BEGIN

if @Owner=@OldOwner

begin

set @OwnerName = @OldOwner + '.' + rtrim(@Name)

exec sp_changeobjectowner @OwnerName, @NewOwner

end

-- select @name,@NewOwner,@OldOwner

FETCH NEXT FROM curObject INTO @Name, @Owner

END

close curObject

deallocate curObject

GO

10、SQL SERVER中直接循環(huán)寫(xiě)入數(shù)據(jù)

declare @i int

set @i=1

while @i<30

begin

insert into test (userid) values(@i)

set @i=@i+1

end

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