- 論壇徽章:
- 0
|
-SQL語句參考手冊2010-12-03 22:30一、基礎(chǔ)1、說明:創(chuàng)建數(shù)據(jù)庫CREATE DATABASE database-name 2、說明:刪除數(shù)據(jù)庫drop database dbname3、說明:備份sql server--- 創(chuàng)建 備份數(shù)據(jù)的 deviceUSE masterEXEC 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 only5、說明:刪除新表drop table tabname 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(shù)據(jù)類型也不能改變,唯一能改變的是增加varchar類型的長度。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 viewname10、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(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。簊elect min(field1) as minvalue from table111、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(jié)果表(例如 TABLE1 和 TABLE2)并消去表中任何重復(fù)行而派生出一個結(jié)果表。當(dāng) ALL 隨 UNION 一起使用時(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(fù)行而派生出一個結(jié)果表。當(dāng) ALL 隨 EXCEPT 一起使用時 (EXCEPT ALL),不消除重復(fù)行。 C: INTERSECT 運算符INTERSECT 運算符通過只包括 TABLE1 和 TABLE2 中都有的行并消除所有重復(fù)行而派生出一個結(jié)果表。當(dāng) ALL 隨 INTERSECT 一起使用時 (INTERSECT ALL),不消除重復(fù)行。 注:使用運算詞的幾個查詢結(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.cB: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/cross (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。12、分組:Group by:一張表,一旦分組 完成后,查詢后只能得到組相關(guān)的信息。組相關(guān)的信息:(統(tǒng)計信息) count,sum,max,min,avg 分組的標(biāo)準(zhǔn)) 在SQLServer中分組時:不能以text,ntext,image類型的字段作為分組依據(jù)在selecte統(tǒng)計函數(shù)中的字段,不能和普通的字段放在一起;13、對數(shù)據(jù)庫進(jìn)行操作:分離數(shù)據(jù)庫: sp_detach_db; 附加數(shù)據(jù)庫:sp_attach_db 后接表明,附加需要完整的路徑名14.如何修改數(shù)據(jù)庫的名稱:sp_renamedb 'old_name', 'new_name'
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(僅用于SQlServer)法二:select top 0 * into b from a2、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)庫之間表的拷貝(具體數(shù)據(jù)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(shù)據(jù)庫’ 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)時間select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b6、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.c7、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)范圍時包括了邊界值,not between不包括select * from table1 where time between time1 and time2select a,b,c, from table1 where a not between 數(shù)值1 and 數(shù)值29、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開始時間,getdate())>513、說明:一條sql 語句搞定數(shù)據(jù)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.排序字段具體實現(xiàn):關(guān)于數(shù)據(jù)庫分頁: declare @start int,@end int @sql nvarchar(600) set @sql=’select top’+str(@end-@start+1)+’+from T where rid not in(select top’+str(@str-1)+’Rid from T where Rid>-1)’ exec sp_executesql @sql
注意:在top后不能直接跟一個變量,所以在實際應(yīng)用中只有這樣的進(jìn)行特殊的處理。Rid為一個標(biāo)識列,如果top后還有具體的字段,這樣做是非常有好處的。因為這樣可以避免 top的字段如果是邏輯索引的,查詢的結(jié)果后實際表中的不一致(邏輯索引中的數(shù)據(jù)有可能和數(shù)據(jù)表中的不一致,而查詢時如果處在索引則首先查詢索引)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)行而派生出一個結(jié)果表(select a from tableA ) except (select a from tableB) except (select a from tableC)17、說明:隨機取出10條數(shù)據(jù)select top 10 * from tablename order by newid()18、說明:隨機選擇記錄select newid()19、說明:刪除重復(fù)記錄1),delete from tablename where id not in (select max(id) from tablename group by col1,col2,...)2),select distinct * into temp from tablename delete from tablename insert into tablename select * from temp評價: 這種操作牽連大量的數(shù)據(jù)的移動,這種做法不適合大容量但數(shù)據(jù)操作3),例如:在一個外部表中導(dǎo)入數(shù)據(jù),由于某些原因第一次只導(dǎo)入了一部分,但很難判斷具體位置,這樣只有在下一次全部導(dǎo)入,這樣也就產(chǎn)生好多重復(fù)的字段,怎樣刪除重復(fù)字段alter table tablename--添加一個自增列add column_b int identity(1,1)delete from tablename where column_b not in(select max(column_b) from tablename group by column1,column2,...)alter table tablename drop column column_b20、說明:列出數(shù)據(jù)庫里所有的表名select name from sysobjects where type='U' // U代表用戶21、說明:列出表里的所有的列名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 B 3手機 C 323、說明:初始化表table1TRUNCATE TABLE table124、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語句組合時用的較多“where 1=1” 是表示選擇全部 “where 1=2”全部不選,如:if @strWhere !='' beginset @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere endelse beginset @strSQL = 'select count(*) as Total from [' + @tblName + ']' end 我們可以直接寫成錯誤!未找到目錄項。set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere 2、收縮數(shù)據(jù)庫--重建索引DBCC REINDEXDBCC INDEXDEFRAG--收縮數(shù)據(jù)和日志DBCC SHRINKDBDBCC SHRINKFILE3、壓縮數(shù)據(jù)庫dbcc shrinkdatabase(dbname)4、轉(zhuǎn)移數(shù)據(jù)庫給新用戶以已存在用戶權(quán)限exec sp_change_users_login 'update_one','newname','oldname'go5、檢查備份集RESTORE VERIFYONLY from disk='E:\dvbbs.bak'6、修復(fù)數(shù)據(jù)庫ALTER DATABASE [dvbbs] SET SINGLE_USERGODBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCKGOALTER DATABASE [dvbbs] SET MULTI_USERGO7、日志清除SET NOCOUNT ONDECLARE @LogicalFileName sysname,@MaxMinutes INT,@NewSize INT
USE tablename -- 要操作的數(shù)據(jù)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(shè)定的日志文件的大小(M)Setup / initializeDECLARE @OriginalSize intSELECT @OriginalSize = size FROM sysfilesWHERE name = @LogicalFileNameSELECT 'Original Size of ' + db_name() + ' LOG is ' + CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB'FROM sysfilesWHERE name = @LogicalFileNameCREATE 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 expiredAND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) AND (@OriginalSize * 8 /1024) > @NewSize BEGIN -- Outer loop.SELECT @Counter = 0WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000))BEGIN -- updateINSERT DummyTrans VALUES ('Fill Log') DELETE DummyTransSELECT @Counter = @Counter + 1ENDEXEC (@TruncLog) ENDSELECT '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 = @LogicalFileNameDROP TABLE DummyTransSET NOCOUNT OFF 8、說明:更改某個表exec sp_changeobjectowner 'tablename','dbo'9、存儲更改全部表CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch@OldOwner as NVARCHAR(12 ,@NewOwner as NVARCHAR(12 ASDECLARE @Name as NVARCHAR(12 DECLARE @Owner as NVARCHAR(12 DECLARE @OwnerName as NVARCHAR(12 DECLARE curObject CURSOR FOR select 'Name' = name, 'Owner' = user_name(uid)from sysobjectswhere user_name(uid)=@OldOwnerorder by nameOPEN curObjectFETCH NEXT FROM curObject INTO @Name, @OwnerWHILE(@@FETCH_STATUS=0)BEGIN if @Owner=@OldOwner begin set @OwnerName = @OldOwner + '.' + rtrim(@Name) exec sp_changeobjectowner @OwnerName, @NewOwnerend-- select @name,@NewOwner,@OldOwnerFETCH NEXT FROM curObject INTO @Name, @OwnerENDclose curObjectdeallocate curObjectGO
10、SQL SERVER中直接循環(huán)寫入數(shù)據(jù)declare @i intset @i=1while @i<30begin insert into test (userid) values(@i) set @i=@i+1end案例:有如下表,要求就裱中所有沒有及格的成績,在每次增長0.1的基礎(chǔ)上,使他們剛好及格:Name scoreZhangshan80Lishi 59Wangwu 50Songquan69while((select min(score) from tb_table)<60)beginupdate tb_table set score =score*1.01 where score<60if (select min(score) from tb_table)>60 breakelse continueend
數(shù)據(jù)開發(fā)-經(jīng)典
1.按姓氏筆畫排序:Select * From TableName Order By CustomerName Collate Chinese_PRC_Stroke_ci_as //從少到多2.數(shù)據(jù)庫加密:select encrypt('原始密碼')select pwdencrypt('原始密碼')select pwdcompare('原始密碼','加密后密碼') = 1--相同;否則不相同 encrypt('原始密碼')select pwdencrypt('原始密碼')select pwdcompare('原始密碼','加密后密碼') = 1--相同;否則不相同3.取回表中字段:declare @list varchar(1000),@sql nvarchar(1000) select @list=@list+','+b.name from sysobjects a,syscolumns b where a.id=b.id and a.name='表A'set @sql='select '+right(@list,len(@list)-1)+' from 表A' exec (@sql)4.查看硬盤分區(qū):EXEC master..xp_fixeddrives5.比較A,B表是否相等:if (select checksum_agg(binary_checksum(*)) from A) = (select checksum_agg(binary_checksum(*)) from B)print '相等'elseprint '不相等'6.殺掉所有的事件探察器進(jìn)程 ECLARE hcforeach CURSOR GLOBAL FOR SELECT 'kill '+RTRIM(spid) FROM master.dbo.sysprocessesWHERE program_name IN('SQL profiler',N'SQL 事件探查器')EXEC sp_msforeach_worker '?'7.記錄搜索:開頭到N條記錄Select Top N * From 表-------------------------------N到M條記錄(要有主索引ID)Select Top M-N * From 表 Where ID in (Select Top M ID From 表) Order by ID Desc----------------------------------N到結(jié)尾記錄Select Top N * From 表 Order by ID Desc案例例如1:一張表有一萬多條記錄,表的第一個字段 RecID 是自增長字段, 寫一個SQL語句, 找出表的第31到第40個記錄。select top 10 recid from A where recid not in(select top 30 recid from A)分析:如果這樣寫會產(chǎn)生某些問題,如果recid在表中存在邏輯索引。select top 10 recid from A where……是從索引中查找,而后面的select top 30 recid from A則在數(shù)據(jù)表中查找,這樣由于索引中的順序有可能和數(shù)據(jù)表中的不一致,這樣就導(dǎo)致查詢到的不是本來的欲得到的數(shù)據(jù)。解決方案1,用order by select top 30 recid from A order by ricid 如果該字段不是自增長,就會出現(xiàn)問題2,在那個子查詢中也加條件:select top 30 recid from A where recid>-1例2:查詢表中的最后以條記錄,并不知道這個表共有多少數(shù)據(jù),以及表結(jié)構(gòu)。set @s = 'select top 1 * from T where pid not in (select top ' + str(@count-1) + ' pid from T)'print @s exec sp_executesql @s9:獲取當(dāng)前數(shù)據(jù)庫中的所有用戶表select Name from sysobjects where xtype='u' and status>=010:獲取某一個表的所有字段select name from syscolumns where id=object_id('表名')select name from syscolumns where id in (select id from sysobjects where type = 'u' and name = '表名')兩種方式的效果相同11:查看與某一個表相關(guān)的視圖、存儲過程、函數(shù)select a.* from sysobjects a, syscomments b where a.id = b.id and b.text like '%表名%'12:查看當(dāng)前數(shù)據(jù)庫中所有存儲過程select name as 存儲過程名稱 from sysobjects where xtype='P'13:查詢用戶創(chuàng)建的所有數(shù)據(jù)庫select * from master..sysdatabases D where sid not in(select sid from master..syslogins where name='sa')或者select dbid, name AS DB_NAME from master..sysdatabases where sid <> 0x0114:查詢某一個表的字段和數(shù)據(jù)類型select column_name,data_type from information_schema.columnswhere table_name = '表名' 15:不同服務(wù)器數(shù)據(jù)庫之間的數(shù)據(jù)操作--創(chuàng)建鏈接服務(wù)器 exec sp_addlinkedserver 'ITSV ', ' ', 'SQLOLEDB ', '遠(yuǎn)程服務(wù)器名或ip地址 ' exec sp_addlinkedsrvlogin 'ITSV ', 'false ',null, '用戶名 ', '密碼 ' --查詢示例 select * from ITSV.數(shù)據(jù)庫名.dbo.表名 --導(dǎo)入示例 select * into 表 from ITSV.數(shù)據(jù)庫名.dbo.表名 --以后不再使用時刪除鏈接服務(wù)器 exec sp_dropserver 'ITSV ', 'droplogins '
--連接遠(yuǎn)程/局域網(wǎng)數(shù)據(jù)(openrowset/openquery/opendatasource) --1、openrowset --查詢示例 select * from openrowset( 'SQLOLEDB ', 'sql服務(wù)器名 '; '用戶名 '; '密碼 ',數(shù)據(jù)庫名.dbo.表名) --生成本地表 select * into 表 from openrowset( 'SQLOLEDB ', 'sql服務(wù)器名 '; '用戶名 '; '密碼 ',數(shù)據(jù)庫名.dbo.表名) |
|