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数据库基本----SQL语句大全

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數據庫基本SQL語句大全

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一、基礎

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??? 1、說明:創建數據庫

??? Create DATABASE database-name

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??? 2、說明:刪除數據庫

??? drop database dbname

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??? 3、說明:備份sql server

??? --- 創建 備份數據的 device

??? USE master

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

??? --- 開始 備份

??? BACKUP DATABASE pubs TO testBack

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??? 4、說明:創建新表

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

??? 根據已有的表創建新表:

??? Acreate table tab_new like tab_old (使用舊表創建新表)

??? Bcreate table tab_new as select col1,col2 from tab_old definition only

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??? 5、說明:刪除新表

??? drop table tabname

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??? 6、說明:增加一個列

??? Alter table tabname add column col type

??? 注:列增加后將不能刪除。DB2中列加上后數據類型也不能改變,唯一能改變的是增加varchar類型的長度。

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??? 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)

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??? 8、說明:創建索引: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。

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??? 9、說明:創建視圖:create view viewname as select statement

??? 刪除視圖:drop view viewname

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??? 10、說明:幾個簡單的基本的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: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

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??? 11、說明:幾個高級查詢運算詞

??? A UNION 運算符

??? UNION 運算符通過組合其他兩個結果表(例如 TABLE1 TABLE2)并消去表中任何重復行而派生出一個結果表。當 ALL UNION 一起使用時(即 UNION ALL),不消除重復行。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復行而派生出一個結果表。當 ALL EXCEPT 一起使用時 (EXCEPT ALL),不消除重復行。

??? C INTERSECT 運算符

??? INTERSECT 運算符通過只包括 TABLE1 TABLE2 中都有的行并消除所有重復行而派生出一個結果表。當 ALL INTERSECT 一起使用時 (INTERSECT ALL),不消除重復

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行。注:使用運算詞的幾個查詢結果行必須是一致的。

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??? 12、說明:使用外連接

??? Aleft outer join

??? 左外連接(左連接):結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

??? Bright outer join:

??? 右外連接(右連接):結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。

??? Cfull outer join

??? 全外連接:不僅包括符號連接表的匹配行,還包括兩個連接表中的所有記錄。

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二、提升

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??? 1、說明:復制表(只復制結構,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

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??? 2、說明:拷貝表(拷貝數據,源表名:a 目標表名:b) (Access可用)

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

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??? 3、說明:跨數據庫之間表的拷貝(具體數據使用絕對路徑) (Access可用)

??? insert into b(a, b, c) select d,e,f from b in ‘具體數據庫’ where 條件

??? 例子:..from b in '"&Server.MapPath("."&"/data.mdb" &"' where..

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??? 4、說明:子查詢(表名1a 表名2b)

??? 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)

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??? 5、說明:顯示文章、提交人和最后回復時間

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

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??? 6、說明:外連接查詢(表名1a 表名2b)

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

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??? 7、說明:在線視圖查詢(表名1a

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

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??? 8、說明:between的用法,between限制查詢數據范圍時包括了邊界值,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

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??? 9、說明:in 的使用方法

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

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??? 10、說明:兩張關聯表,刪除主表中已經在副表中沒有的信息

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

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??? 11、說明:四表聯查問題:

??? 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 ..

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??? 12、說明:日程安排提前五分鐘提醒

??? select * from 日程安排 where datediff('minute',f開始時間,getdate())>5

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??? 13、說明:一條sql 語句搞定數據庫分頁

??? 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

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??? 14、說明:前10條記錄

??? select top 10 * form table1 where 范圍

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??? 15、說明:選擇在每一組b值相同的數據中對應的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)

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??? 16、說明:包括所有在 TableA 中但不在 TableBTableC 中的行并消除所有重復行而派生出一個結果表

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

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??? 17、說明:隨機取出10條數據

??? select top 10 * from tablename order by newid()

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??? 18、說明:隨機選擇記錄

??? select newid()

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??? 19、說明:刪除重復記錄

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

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??? 20、說明:列出數據庫里所有的表名

??? select name from sysobjects where type='U'

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??? 21、說明:列出表里的所有的

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

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??? 22、說明:列示typevenderpcs字段,以type字段排列,case可以方便地實現多重選擇,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)

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FROM tablename group by type

??? 顯示結果:

??? type vender pcs

??? 電腦 A 1

??? 電腦 A 1

??? 光盤 B 2

??? 光盤 A 2

??? 手機 B 3

??? 手機 C 3

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??? 23、說明:初始化表table1

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??? TRUNCATE TABLE table1

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??? 24、說明:選擇從1015的記錄

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

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三、技巧

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??? 11=11=2的使用,在SQL語句組合時用的較多

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??? 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

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??? 我們可以直接寫成

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

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??? 2、收縮數據庫

??? --重建索引

??? DBCC REINDEX

??? DBCC INDEXDEFRAG

??? --收縮數據和日志

??? DBCC SHRINKDB

??? DBCC SHRINKFILE

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??? 3、壓縮數據庫

??? dbcc shrinkdatabase(dbname)

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??? 4、轉移數據庫給新用戶以已存在用戶權限

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

??? go

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??? 5、檢查備份集

??? RESTORE VERIFYONLY from disk='E:/dvbbs.bak'

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??? 6、修復數據庫

??? Alter DATABASE [dvbbs] SET SINGLE_USER

??? GO

??? DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK

??? GO

??? Alter DATABASE [dvbbs] SET MULTI_USER

??? GO

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??? 7、日志清除

??? SET NOCOUNT ON

??? DECLARE @LogicalFileName sysname,

???????????? @MaxMinutes INT,

???????????? @NewSize INT

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??? USE???? tablename???????????? -- 要操作的數據庫名

??? Select?? @LogicalFileName = 'tablename_log',?? -- 日志文件名

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

???????????? @NewSize = 1?????????????????? -- 你想設定的日志文件的大小(M)

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??? -- 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)

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??? DECLARE @Counter?? INT,

???????????? @StartTime DATETIME,

???????????? @TruncLog?? VARCHAR(255)

??? Select? ?@StartTime = GETDATE(),

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

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??? 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

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??? 8、說明:更改某個表

??? exec sp_changeobjectowner 'tablename','dbo'

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??? 9、存儲更改全部表

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??? Create PROCEDURE dbo.User_ChangeObjectOwnerBatch

??? @OldOwner as NVARCHAR(128),

??? @NewOwner as NVARCHAR(128)

??? AS

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??? DECLARE @Name?? as NVARCHAR(128)

??? DECLARE @Owner?? as NVARCHAR(128)

??? DECLARE @OwnerName?? as NVARCHAR(128)

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??? DECLARE curObject CURSOR FOR

??? select 'Name'?? = name,

?????? 'Owner'?? = user_name(uid)

??? from sysobjects

??? where user_name(uid)=@OldOwner

??? order by name

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??? 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

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??? FETCH NEXT FROM curObject INTO @Name, @Owner

??? END

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??? close curObject

??? deallocate curObject

??? GO

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??? 10SQL SERVER中直接循環寫入數據

??? 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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聲明:本帖轉自 http://tech.it168.com/KnowledgeBase/Articles/0/f/4/0f4b49668cf2e2281d956c903d650be7.htm

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原帖地址不詳,在此對本貼原作者致以誠摯的謝意!

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本文來自CSDN博客,轉載請標明出處:http://blog.csdn.net/moonboy2050/archive/2009/08/01/4400428.aspx

轉載于:https://www.cnblogs.com/wdpp/archive/2009/08/15/2387043.html

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