数据库基本----SQL语句大全
數(shù)據(jù)庫基本SQL語句大全
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一、基礎(chǔ)
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??? 1、說明:創(chuàng)建數(shù)據(jù)庫
??? Create DATABASE database-name
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??? 2、說明:刪除數(shù)據(jù)庫
??? drop database dbname
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??? 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
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??? 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
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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(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。
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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(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。
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??? 9、說明:創(chuàng)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(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
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??? 11、說明:幾個高級查詢運(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(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(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)行而派生出一個結(jié)果表。當(dāng) ALL 隨 INTERSECT 一起使用時 (INTERSECT ALL),不消除重復(fù)
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行。注:使用運(yùn)算詞的幾個查詢結(jié)果行必須是一致的。
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??? 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(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
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??? 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;
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??? 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..
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??? 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)
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??? 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) b
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??? 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
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??? 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;
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??? 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 time2
??? select a,b,c, from table1 where a not between 數(shù)值1 and 數(shù)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(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
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??? 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 ..
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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(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
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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(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)
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??? 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)
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??? 17、說明:隨機(jī)取出10條數(shù)據(jù)
??? select top 10 * from tablename order by newid()
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??? 18、說明:隨機(jī)選擇記錄
??? select newid()
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??? 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,)
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??? 20、說明:列出數(shù)據(jù)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)
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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
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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
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三、技巧
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??? 1、1=1,1=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(shù)據(jù)庫
??? --重建索引
??? DBCC REINDEX
??? DBCC INDEXDEFRAG
??? --收縮數(shù)據(jù)和日志
??? DBCC SHRINKDB
??? DBCC SHRINKFILE
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??? 3、壓縮數(shù)據(jù)庫
??? dbcc shrinkdatabase(dbname)
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??? 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'
??? 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(fù)數(shù)據(jù)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(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)
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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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??? 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
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聲明:本帖轉(zhuǎn)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(zhuǎn)載請標(biāo)明出處:http://blog.csdn.net/moonboy2050/archive/2009/08/01/4400428.aspx
轉(zhuǎn)載于:https://www.cnblogs.com/wdpp/archive/2009/08/15/2387043.html
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