SQL语句先前写的时候,很容易把一些特殊的用法忘记,我特此整理了一下SQL语句操作。 Zxh<pd25Y
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一、基础 *Sps^Wl
1、说明:创建数据库 h
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CREATE DATABASE database-name zI4d|P
2、说明:删除数据库 9 !$&1|,*
drop database dbname ~BMUea(
3、说明:备份sql server 8.Ufw.
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--- 创建 备份数据的 device AG><5 }
USE master 2D/bMq
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' Xyjd7"
--- 开始 备份 -kHJH><j
BACKUP DATABASE pubs TO testBack _=}.Sg5Q
4、说明:创建新表 g'cVsO)S
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) aW9\h_$
根据已有的表创建新表: xjD."q
A:create table tab_new like tab_old (使用旧表创建新表) ~O|~M_Z
B:create table tab_new as select col1,col2... from tab_old definition only z_Hkw3?
5、说明:删除新表 &OA6Zw/A
drop table tabname 3)I]bui
6、说明:增加一个列 @saK:z
Alter table tabname add column col type @WNqD*)1
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。
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7、说明:添加主键: Alter table tabname add primary key(col) 2MmHO2
说明:删除主键: Alter table tabname drop primary key(col) bOSqD[?
8、说明:创建索引:create [unique] index idxname on tabname(col....) bo1J'pU
删除索引:drop index idxname &j,#5f(
注:索引是不可更改的,想更改必须删除重新建。 cg_ " }]Y1
9、说明:创建视图:create view viewname as select statement d"L(eI}G
删除视图:drop view viewname (4?^X
10、说明:几个简单的基本的sql语句 =cO5Nt
选择:select * from table1 where 范围 IwRP,MQ~
插入:insert into table1(field1,field2) values(value1,value2) rgDl%X2B
删除:delete from table1 where 范围 >@Pw{Zh$
更新:update table1 set field1=value1 where 范围 MJkusR/
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! &XCP@@T
排序:select * from table1 order by field1,field2 [desc] {Qc,Nl
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总数:select count as totalcount from table1 xojt s;n
求和:select sum(field1) as sumvalue from table1 Mdq|:^px
平均:select avg(field1) as avgvalue from table1 Z_fwvcZ?05
最大:select max(field1) as maxvalue from table1 P^!g0K
最小:select min(field1) as minvalue from table1 ,:2Z6~z{
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11、说明:几个高级查询运算词 ug.|ag'R
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A: UNION 运算符 ~f"3Wa*\B
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 kR3wbA
B: EXCEPT 运算符 %a|Qw(4\
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 oUO3,2bn
C: INTERSECT 运算符 J%n#uUs
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 l fFRqZ
注:使用运算词的几个查询结果行必须是一致的。 @,7r<6E
12、说明:使用外连接 P_'{|M<?
A、left outer join: -v-kFzu
左外连接(左连接):结果集几包括连接表的匹配行,也包括左连接表的所有行。 ![$`Ivro`
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 [+QyKyhTO
B:right outer join: `wZ
右外连接(右连接):结果集既包括连接表的匹配连接行,也包括右连接表的所有行。 8:)[.
C:full outer join: 9HEqB0|ZRu
全外连接:不仅包括符号连接表的匹配行,还包括两个连接表中的所有记录。 7r^Cs#b+I
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二、提升 RyU8{-q
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) 5*+DN
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法一:select * into b from a where 1<>1 'J3yJ{
法二:select top 0 * into b from a !Z |_3
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) 4_ypFuS ^
insert into b(a, b, c) select d,e,f from b; [VqiF~o,
3、说明:跨数据库之间表的拷贝(具体数据使用绝对路径) (Access可用) A FBH(ms't
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 O2?yI8|Jn
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. o.w/?
4、说明:子查询(表名1:a 表名2:b) SP/b4
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) y10W\beJ
5、说明:显示文章、提交人和最后回复时间 [PB73q8
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b {&XTa`C
6、说明:外连接查询(表名1:a 表名2:b) tzfyS#E
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c B9[vv;lzu
7、说明:在线视图查询(表名1:a ) ~cyKPg6
select * from (SELECT a,b,c FROM a) T where t.a > 1; ^#C+l
8、说明:between的用法,between限制查询数据范围时包括了边界值,not between不包括 U;TS7A3
select * from table1 where time between time1 and time2 |vm-(HY!
select a,b,c, from table1 where a not between 数值1 and 数值2 jSM`bE+"
9、说明:in 的使用方法 OI*ltba?
select * from table1 where a [not] in ('值1','值2','值4','值6') Ly3!0P.<
10、说明:两张关联表,删除主表中已经在副表中没有的信息 d}tmZ*q
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) 4n@>gW
11、说明:四表联查问题: uD?RL~M
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 ..... \At~94
12、说明:日程安排提前五分钟提醒 .ahY 1CO
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 \!30t1EZ
13、说明:一条sql 语句搞定数据库分页 $]Ix(7@W
select top 10 b.* from (select top 20 主键字段,排序字段 from 表名 order by 排序字段 desc) a,表名 b where b.主键字段 = a.主键字段 order by a.排序字段 tu"-]^
14、说明:前10条记录 1*G&ZI
select top 10 * form table1 where 范围 p`rjWpH
15、说明:选择在每一组b值相同的数据中对应的a最大的记录的所有信息(类似这样的用法可以用于论坛每月排行榜,每月热销产品分析,按科目成绩排名,等等.) U,7
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) jnbR}a=fJ
16、说明:包括所有在 TableA 中但不在 TableB和TableC 中的行并消除所有重复行而派生出一个结果表 >~Gy+-
(select a from tableA ) except (select a from tableB) except (select a from tableC) ;?@Rq"*
17、说明:随机取出10条数据 8(l0\R,%+z
select top 10 * from tablename order by newid() 5'+g[eNyBV
18、说明:随机选择记录 }No #_{
select newid() R.2i%cU
19、说明:删除重复记录 n0gjcDHQ
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) -?:8sv*X
20、说明:列出数据库里所有的表名 1Az&BZU[
select name from sysobjects where type='U' qTRP2rH,L&
21、说明:列出表里的所有的 h.]^ o*DJ
select name from syscolumns where id=object_id('TableName') SmD#hE[
22、说明:列示type、vender、pcs字段,以type字段排列,case可以方便地实现多重选择,类似select 中的case。 \)wVO*9*0
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 v;5-1
显示结果: Q]GS#n
type vender pcs ks("(
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电脑 A 1 wJJ|]^0.
电脑 A 1 p>\[[Md
光盘 B 2 /m;Bwu
光盘 A 2 A^+k A)8
手机 B 3 -T1R}ew*t
手机 C 3 l3BN,HNv+
23、说明:初始化表table1 l3u+fE,;_
TRUNCATE TABLE table1 568M4xzi
24、说明:选择从10到15的记录 XUh&an$
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc Ye4
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三、技巧 T+~&jC:{
1、1=1,1=2的使用,在SQL语句组合时用的较多 aM1WC 'c&)
"where 1=1" 是表示选择全部 "where 1=2"全部不选, Qj1%'wWG
如: Lg,ObVt!
if @strWhere !='' 0PFC%x
begin D4(73
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere frm[<-~ w0
end bv(+$YR
else 0%,W5w
begin YfZ5Q}*1O+
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' ib
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end 2-qWR<E
我们可以直接写成 42hG}Gt
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere f%t
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2、收缩数据库 9[*P`*&
--重建索引 3hBYx@jTO
DBCC REINDEX RrrlfF ms
DBCC INDEXDEFRAG 0Bp0ScE|FA
--收缩数据和日志 7Dl^5q.|
DBCC SHRINKDB 'Kkp!eZQ~
DBCC SHRINKFILE I]5){Q"S
3、压缩数据库 h(}#s1Fzq
dbcc shrinkdatabase(dbname) >
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4、转移数据库给新用户以已存在用户权限 H(--hG5}
exec sp_change_users_login 'update_one','newname','oldname' u81F^72U
go {yT<22Fl
5、检查备份集 8KigGhY'ms
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' +/%4E %
6、修复数据库 Pq35w#`!
ALTER DATABASE [dvbbs] SET SINGLE_USER _X<V`,
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GO 5>CeFy
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK ,K6ODtw.
GO k5bv57@
ALTER DATABASE [dvbbs] SET MULTI_USER h82y9($cZ
GO &WAU[{4W
7、日志清除 +/n]9l]#h
SET NOCOUNT ON $^ir3f+
DECLARE @LogicalFileName sysname, KYKF$@
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@MaxMinutes INT, ]v@ng8
@NewSize INT }3XjP55
USE tablename -- 要操作的数据库名 cdH`#X
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 -gC%*S5&
@MaxMinutes = 10, -- Limit on time allowed to wrap log. ho~WD'i
@NewSize = 1 -- 你想设定的日志文件的大小(M) L{&1w
-- Setup / initialize gMq;
DECLARE @OriginalSize int ,g?M[(wtc
SELECT @OriginalSize = size `Has3AX8
FROM sysfiles 1
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WHERE name = @LogicalFileName HlkjyD8
SELECT 'Original Size of ' + db_name() + ' LOG is ' + &.z-itiV
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + *"F*6+}w"
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB' h<?I?ZR0$
FROM sysfiles wV$V X
WHERE name = @LogicalFileName _h=h43'3
CREATE TABLE DummyTrans s:,fXg25J
(DummyColumn char (8000) not null) GO][`zZJ]
DECLARE @Counter INT, XM?c*,=fu
@StartTime DATETIME, p((. (fx
@TruncLog VARCHAR(255) P??pWzb6HH
SELECT @StartTime = GETDATE(), ?H!&4o
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' n
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DBCC SHRINKFILE (@LogicalFileName, @NewSize) T?u*ey~Tv
EXEC (@TruncLog) /Z#AHfKF
-- Wrap the log if necessary. 93w$ck},?G
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired e*Nm[*@UW
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) MfLus40;n
AND (@OriginalSize * 8 /1024) > @NewSize l{ fL~O
BEGIN -- Outer loop. SFsT^f<
SELECT @Counter = 0 sZqi)lo-s
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) G~*R6x2g
BEGIN -- update YWi Y[
INSERT DummyTrans VALUES ('Fill Log') CSm(yB{|pC
DELETE DummyTrans \4 t;{_
SELECT @Counter = @Counter + 1 JL:B4f%}B
END yFFNzw{
EXEC (@TruncLog) T%}x%9VO7
END x5U;i
SELECT 'Final Size of ' + db_name() + ' LOG is ' + ,(c'h:@M
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + l~kxK.Ru
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' ^MT20pL
FROM sysfiles Dn~t _n
WHERE name = @LogicalFileName &|zV Wl
DROP TABLE DummyTrans 5KYR"-jY
SET NOCOUNT OFF u<j.XPK
8、说明:更改某个表 }zeKf/?'
exec sp_changeobjectowner 'tablename','dbo' Xa>c]j
9、存储更改全部表 E*9W'e~=
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch =`gFwH<
@OldOwner as NVARCHAR(128), `wLmGv+V
@NewOwner as NVARCHAR(128) u8y('\(
AS 2@ZuH^qhk
DECLARE @Name as NVARCHAR(128) CFY4PuI"!
DECLARE @Owner as NVARCHAR(128) a[lx&CHgI
DECLARE @OwnerName as NVARCHAR(128) ZhoB/TgdL
DECLARE curObject CURSOR FOR wYHyVY2tj2
select 'Name' = name, iqXsDgkr
'Owner' = user_name(uid) tjm@+xs
from sysobjects FW<YN;
where user_name(uid)=@OldOwner Gh'{O/F4*
order by name :J5CmU$
OPEN curObject wLQM]$O
FETCH NEXT FROM curObject INTO @Name, @Owner (%M:=zm
WHILE(@@FETCH_STATUS=0) 9 &Od7Cn
BEGIN _8z
if @Owner=@OldOwner ,(#n8|q4
begin )7rMevF(xJ
set @OwnerName = @OldOwner + '.' + rtrim(@Name) VN@ZYSs
exec sp_changeobjectowner @OwnerName, @NewOwner 5hiuBf<
end zjx'nK{eI
-- select @name,@NewOwner,@OldOwner VK4"
FETCH NEXT FROM curObject INTO @Name, @Owner % o0.8qVJi
END =OA7$z[
close curObject LA837%)
deallocate curObject C9T-4o1
GO gD6BPW~0
10、SQL SERVER中直接循环写入数据 a4!6K
declare @i int -32.g\]
set @i=1 +G!;:o
while @i<30 A)^A2xZQ
begin ?[O Sy.6
insert into test (userid) values(@i) l{\@+m
set @i=@i+1 n8e}8.Bu
end 3Q+THg3~?
小记存储过程中经常用到的本周,本月,本年函数 qSL~A-
Dateadd(wk,datediff(wk,0,getdate()),-1) KH1/B_.\V
Dateadd(wk,datediff(wk,0,getdate()),6) Nx(y_.I{K
Dateadd(mm,datediff(mm,0,getdate()),0) f^XfI H_#
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) !r0 z3^*N
Dateadd(yy,datediff(yy,0,getdate()),0) =j1Q5@vS
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) Aa%ks+1
上面的SQL代码只是一个时间段 ds
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Dateadd(wk,datediff(wk,0,getdate()),-1) fbW#6:Y
Dateadd(wk,datediff(wk,0,getdate()),6) Wuji'sxTs
就是表示本周时间段. MXpj_+@
下面的SQL的条件部分,就是查询时间段在本周范围内的: m=IA/HOR^
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) \RTX fe-`
而在存储过程中 W;wu2 '
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) nHL(v
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) zd[cp@