EXEC(@STRING)
END

GO

--FOREIGN KEY 約束
DECLARE @STRING VARCHAR(8000)
WHILE EXISTS(SELECT NAME FROM SYSOBJECTS WHERE TYPE='F')
BEGIN
 SELECT top 1 @STRING='ALTER TABLE '+B.NAME+' DROP CONSTRAINT '+A.NAME
  FROM (SELECT PARENT_OBJ,NAME FROM SYSOBJECTS WHERE TYPE='F') A,
        (SELECT ID,NAME FROM SYSOBJECTS WHERE OBJECTPROPERTY(ID, N'ISUSERTABLE') = 1) B
    WHERE A.PARENT_OBJ=B.ID
 EXEC(@STRING)
END

GO

--PRIMARY KEY 約束
DECLARE @STRING VARCHAR(8000)
WHILE EXISTS(SELECT NAME FROM SYSOBJECTS WHERE XTYPE='PK')
BEGIN
 SELECT top 1 @STRING='ALTER TABLE '+B.NAME+' DROP CONSTRAINT '+A.NAME
  FROM (SELECT PARENT_OBJ,NAME FROM SYSOBJECTS WHERE XTYPE='PK') A,
        (SELECT ID,NAME FROM SYSOBJECTS WHERE OBJECTPROPERTY(ID, N'ISUSERTABLE') = 1) B
    WHERE A.PARENT_OBJ=B.ID
 EXEC(@STRING)
END

GO

--觸發(fā)器
DECLARE @STRING VARCHAR(8000)
WHILE EXISTS(SELECT NAME FROM SYSOBJECTS WHERE XTYPE='TR')
BEGIN
 SELECT top 1 @STRING='DROP TRIGGER '+NAME FROM SYSOBJECTS WHERE XTYPE='TR'
 EXEC(@STRING)
END

GO

 

--索引
declare @string varchar(8000)
while exists(
 select TABLE_NAME= o.name,INDEX_NAME= x.name 
  from sysobjects o, sysindexes x, syscolumns c, sysindexkeys xk
  where o.type in ('U') 
  and convert(bit,(x.status & 0x800)/0x800)=0
  and x.id = o.id
  and o.id = c.id
  and o.id = xk.id
  and x.indid = xk.indid
  and c.colid = xk.colid
  and xk.keyno <= x.keycnt
  and permissions(o.id, c.name) <> 0
  and     (x.status&32) = 0  -- No hypothetical indexes
  group by o.name,x.name)
begin
select top 1 @string='drop index '+o.name+'.'+ x.name 
  from sysobjects o, sysindexes x, syscolumns c, sysindexkeys xk
  where o.type in ('U') 
  and convert(bit,(x.status & 0x800)/0x800)=0
  and x.id = o.id
  and o.id = c.id
  and o.id = xk.id
  and x.indid = xk.indid
  and c.colid = xk.colid
  and xk.keyno <= x.keycnt
  and permissions(o.id, c.name) <> 0
  and     (x.status&32) = 0  -- No hypothetical indexes
  group by o.name,x.name
exec(@string)
end 

SQL語句先前寫的時(shí)候，很容易把一些特殊的用法忘記，我特此整理了一下SQL語句操作，方便自己寫SQL時(shí)方便一點(diǎn)，想貼上來，一起看看，同時(shí)希望大家能共同多多提意見，也給我留一些更好的佳句，整理一份《精妙SQL速查手冊(cè)》，不吝賜教！ 
一、基礎(chǔ)
1、說明：創(chuàng)建數(shù)據(jù)庫(kù)
Create DATABASE database-name 
2、說明：刪除數(shù)據(jù)庫(kù)
drop database dbname
3、說明：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'
--- 開始 備份
BACKUP DATABASE pubs TO testBack 
4、說明：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、說明：刪除新表
drop table tabname 
6、說明：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)類型也不能改變，唯一能改變的是增加varchar類型的長(zhǎng)度。
7、說明：添加主鍵： Alter table tabname add primary key(col) 
說明：刪除主鍵： Alter table tabname drop primary key(col) 
8、說明：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、說明：創(chuàng)建視圖：create view viewname as select statement 
刪除視圖：drop view viewname
10、說明：幾個(gè)簡(jiǎn)單的基本的sql語句
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、說明：幾個(gè)高級(jí)查詢運(yùn)算詞
A： UNION 運(yùn)算符 
UNION 運(yùn)算符通過組合其他兩個(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自 TABLE1 就是來自 TABLE2。 
B： EXCEPT 運(yùn)算符 
EXCEPT 運(yùn)算符通過包括所有在 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)查詢結(jié)果行必須是一致的。 
12、說明：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、說明：子查詢(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、說明：外連接查詢(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、說明：在線視圖查詢(表名1：a )
select * from (Select a,b,c FROM a) T where t.a > 1;
8、說明：between的用法,between限制查詢數(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、說明：in 的使用方法
select * from table1 where a [not] in (‘值1’,’值2’,’值4’,’值6’)
10、說明：兩張關(guān)聯(lián)表，刪除主表中已經(jīng)在副表中沒有的信息 
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 )
11、說明：四表聯(lián)查問題：
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、說明：日程安排提前五分鐘提醒 
SQL: select * from 日程安排 where datediff('minute',f開始時(shí)間,getdate())>5
13、說明：一條sql 語句搞定數(shù)據(jù)庫(kù)分頁
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、說明：前10條記錄
select top 10 * form table1 where 范圍
15、說明：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(類似這樣的用法可以用于論壇每月排行榜,每月熱銷產(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、說明：隨機(jī)取出10條數(shù)據(jù)
select top 10 * from tablename order by newid()
18、說明：隨機(jī)選擇記錄
select newid()
19、說明：刪除重復(fù)記錄
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...)
20、說明：列出數(shù)據(jù)庫(kù)里所有的表名
select name from sysobjects where type='U' 
21、說明：列出表里的所有的
select name from syscolumns where id=object_id('TableName')
22、說明：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 B 2
光盤 A 2
手機(jī) B 3
手機(jī) C 3
23、說明：初始化表table1
TRUNCATE TABLE table1
24、說明：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)給新用戶以已存在用戶權(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

刪除重復(fù)行
select   distinct   *   into   #t   from   original   
    
  truncate   table   original   
    
  insert   into   original   select   *   fro   #t