建立之前判斷該資料庫是否存在
if exists (select * from sysdatabases where name='databaseName')
drop database databaseName
go
Create DATABASE database-name
drop database dbname
--- 建立備份資料的 device
USE master
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat'
--- 開始備份
BACKUP DATABASE pubs TO testBack
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)
根據已有的表建立新表:
A:go
use 原資料庫名
select * into 目的資料庫名.dbo.目的表名 from 原表名(使用舊表建立新表)
B:create table tab_new as select col1,col2… from tab_old definition only
create sequence SIMON_SEQUENCE
minvalue 1 -- 最小值
maxvalue 999999999999999999999999999 -- 最大值
start with 1 -- 開始值
increment by 1 -- 每次加幾
cache 20;
drop table tabname
Alter table tabname add column col type
Alter table tabname drop column colname
Alter table tabname add primary key(col)
說明:删除主鍵:Alter table tabname drop primary key(col)
create [unique] index idxname on tabname(col…。)
删除索引:drop index idxname on tabname
注:索引是不可更改的,想更改必須删除重建立。
create view viewname as select statement
删除視圖:drop view viewname
(1) 資料記錄篩選:
sql="select * from 資料表 where 字段名=字段值 order by 字段名 [desc]"
sql="select * from 資料表 where 字段名 like '%字段值%' order by 字段名 [desc]"
sql="select top 10 * from 資料表 where 字段名 order by 字段名 [desc]"
sql="select * from 資料表 where 字段名 in ('值1','值2','值3')"
sql="select * from 資料表 where 字段名 between 值1 and 值2"
(2) 更新資料記錄:
sql="update 資料表 set 字段名=字段值 where 條件表達式"
sql="update 資料表 set 字段1=值1,字段2=值2 …… 字段n=值n where 條件表達式"
(3) 删除資料記錄:
sql="delete from 資料表 where 條件表達式"
sql="delete from 資料表" (将資料表所有記錄删除)
(4) 添加資料記錄:
sql="insert into 資料表 (字段1,字段2,字段3 …) values (值1,值2,值3 …)"
sql="insert into 目标資料表 select * from 源資料表" (把源資料表的記錄添加到目标資料表)
(5) 資料記錄統計函數:
AVG(字段名) 得出一個表格欄平均值
COUNT(*¦字段名) 對資料行數的統計或對某一欄有值的資料行數統計
MAX(字段名) 取得一個表格欄最大的值
MIN(字段名) 取得一個表格欄最小的值
SUM(字段名) 把資料欄的值相加
引用以上函數的方法:
sql="select sum(字段名) as 别名 from 資料表 where 條件表達式"
set rs=conn.excute(sql)
用 rs("别名") 擷取統計的值,其它函數運用同上。
查詢去除重複值:select distinct * from table1
(5) 資料表的建立和删除:
CREATE TABLE 資料表名稱(字段1 類型1(長度),字段2 類型2(長度) …… )
A:UNION 運算符
UNION 運算符通過組合其他兩個結果表(例如TABLE1 和TABLE2)并消去表中任何重複行而派生出一個結果表。當 ALL 随UNION 一起使用時(即UNION ALL),不消除重複行。兩種情況下,派生表的每一行不是來自TABLE1 就是來自TABLE2。
B: EXCEPT 運算符
EXCEPT 運算符通過包括所有在TABLE1 中但不在TABLE2 中的行并消除所有重複行而派生出一個結果表。當ALL 随EXCEPT 一起使用時(EXCEPT ALL),不消除重複行。
C:INTERSECT 運算符
INTERSECT 運算符通過隻包括TABLE1 和TABLE2 中都有的行并消除所有重複行而派生出一個結果表。當ALL 随INTERSECT 一起使用時(INTERSECT ALL),不消除重複行。
注:使用運算詞的幾個查詢結果行必須是一緻的。
A、left outer join:
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:
右外連接配接(右連接配接):結果集既包括連接配接表的比對連接配接行,也包括右連接配接表的所有行。
C:full outer join:
全外連接配接:不僅包括符号連接配接表的比對行,還包括兩個連接配接表中的所有記錄。
if exists (select * from sys.databases where name = '資料庫名')
drop database [資料庫名]
if not exists (select * from sysobjects where [name] = '表名' and xtype='U')
begin
--這裡建立表
end
if exists (select * from sysobjects where id = object_id(N'[存儲過程名]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
drop procedure [存儲過程名]
if object_id('tempdb..#臨時表名') is not null
drop table #臨時表名
--SQL Server 2000
IF EXISTS (SELECT * FROM sysviews WHERE object_id = '[dbo].[視圖名]'
--SQL Server 2005
IF EXISTS (SELECT * FROM sys.views WHERE object_id = '[dbo].[視圖名]'
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[函數名]') and xtype in (N'FN', N'IF', N'TF'))
drop function [dbo].[函數名]
SELECT [name],[id],crdate FROM sysobjects where xtype='U'
/*
if exists(select * from syscolumns where id=object_id('表名') and name='列名')
alter table 表名drop column 列名
if columnproperty(object_id('table'),'col','IsIdentity')=1
print '自增列'
else
print '不是自增列'
SELECT * FROM sys.columns WHERE object_id=OBJECT_ID('表名')
AND is_identity=1
if exists(select * from sysindexes where id=object_id('表名') and name='索引名')
print '存在'
print '不存在
SELECT * FROM sys.sysobjects WHERE name='對象名'
select * from table(所要查詢的表名) where coloum(條件)
(隻複制結構,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
(拷貝資料,源表名:a 目标表名:b) (Access可用)
insert into b(x, y, z) select d,e,f from a;
(具體資料使用絕對路徑) (Access可用)
insert into b(x, y, z) select d,e,f from a in ‘具體資料庫’ where 條件
例子:。.from b in '"&Server.MapPath("."&"\data.mdb" &"' where..
(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)
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) 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
(表名1:a
select * from (Select a,b,c FROM a) T where t.a > 1;
between限制查詢資料範圍時包括了邊界值,not between不包括
select * from table1 where time between time1 and time2
select a,b,c, from table1 where a not between 數值1 and 數值2
select * from table1 where a [not] in (‘值1’,’值2’,’值4’,’值6’)
兩張關聯表delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1
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 .....
SQL: select * from 日程安排 where datediff('minute',f開始時間,getdate())>5
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
select top 10 * from table1 where 範圍
選擇在每一組b值相同的資料中對應的a最大的記錄的所有資訊(類似這樣的用法可以用于論壇每月排行榜,每月熱銷産品分析,按科目成績排名,等等。)
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b)
包括所有在TableA 中但不在TableB和TableC 中的行并消除所有重複行而派生出一個結果表
(select a from tableA except (select a from tableB) except (select a from tableC)
select top 10 * from tablename order by newid()
select newid()
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...)
select name from sysobjects where type='U'
select name from syscolumns where id=object_id('TableName')
列示type、vender、pcs字段,以type字段排列,case可以友善地實作多重選擇,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
顯示結果:
type vender pcs
電腦A 1
CD光牒A 2
手機B 3
手機C 3
TRUNCATE TABLE table1
select top 5 * from (select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc) table_2 order by id
declare @numid int
declare @id varchar(50)
set @numid=2005
set @id=convert(varchar,@numid)
通過上述語句完成資料類型Int轉換成varchar,其他轉換類似,可參看convert函數
技巧
在SQL語句組合時用的較多
“where 1=1”是表示選擇全部 “where 1=2”全部不選,
如:
if @strWhere !='
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere
set @strSQL = 'select count(*) as Total from [' + @tblName + ']'
我們可以直接寫成
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 and '+ @strWhere
--重建索引
DBCC REINDEX
DBCC INDEXDEFRAG
--收縮資料和日志
DBCC SHRINKDB
DBCC SHRINKFILE
dbcc shrinkdatabase(dbname)
轉移資料庫給新使用者以已存在使用者權限
exec sp_change_users_login 'update_one','newname','oldname'
RESTORE VERIFYONLY from disk='E:\dvbbs.bak'
Alter DATABASE [dvbbs] SET SINGLE_USER
GO
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK
Alter DATABASE [dvbbs] SET MULTI_USER
SET NOCOUNT ON
DECLARE @LogicalFileName sysname,
@MaxMinutes INT,
@NewSize INT
USE tablename -- 要操作的資料庫名
@MaxMinutes = 10, -- Limit on time allowed to wrap log.
@NewSize = 1 -- 你想設定的日志檔案的大小(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'
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
Select 'Final Size of ' + db_name() + ' LOG is ' +
CONVERT(VARCHAR(30),size) + ' 8K pages or ' +
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB'
Drop TABLE DummyTrans
SET NOCOUNT OFF
exec sp_changeobjectowner 'tablename','dbo'
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
set @OwnerName = @OldOwner + '.' + rtrim(@Name)
exec sp_changeobjectowner @OwnerName, @NewOwner
-- select @name,@NewOwner,@OldOwner
close curObject
deallocate curObject
declare @i int
set @i=1
while @i<30
insert into test (userid) values(@i)
set @i=@i+1