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。 |(O _K(
H<bB@(i
0ZjinWkR[
一、基础 9{XC9\~
1、说明:创建数据库 pTIE.:g(
CREATE DATABASE database-name ,5/zTLd
2、说明:删除数据库 ahqsbNu1
drop database dbname j;_
>,\
3、说明:备份sql server A"R5Fd%6pc
--- 创建 备份数据的 device Q:sw*7"F
USE master 6qkMB|@Ix
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' $(ei<cAV
--- 开始 备份 R,KoymXP
BACKUP DATABASE pubs TO testBack LGF5yRk
4、说明:创建新表 #ybtjsu'"U
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) M_EXA _
根据已有的表创建新表: g=_@j`
A:create table tab_new like tab_old (使用旧表创建新表) >Mc,c(CvU
B:create table tab_new as select col1,col2... from tab_old definition only P q)C(Z
5、说明:删除新表 MPF;P&6
drop table tabname =r1@?x
6、说明:增加一个列 .m_-L
Y-
Alter table tabname add column col type |)IS[:X
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。 [SX>b"L
7、说明:添加主键: Alter table tabname add primary key(col) 8sGaq [
说明:删除主键: Alter table tabname drop primary key(col) *:hHlH* t1
8、说明:创建索引:create [unique] index idxname on tabname(col....) 5p`.RWls
删除索引:drop index idxname D_)n\(3
注:索引是不可更改的,想更改必须删除重新建。 zTQTmO
9、说明:创建视图:create view viewname as select statement c&n.JV
删除视图:drop view viewname '}.Z' %;
10、说明:几个简单的基本的sql语句 !pG_MO
选择:select * from table1 where 范围 \oc*
插入:insert into table1(field1,field2) values(value1,value2) l8Ks{(wh
删除:delete from table1 where 范围 QeZK&^W
更新:update table1 set field1=value1 where 范围 v35=4>Y
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! Ht!]%
排序:select * from table1 order by field1,field2 [desc] S1oP_A[|
总数:select count as totalcount from table1 Qfd4")zhG
求和:select sum(field1) as sumvalue from table1 13KfI
平均:select avg(field1) as avgvalue from table1 'Z=8no`<
最大:select max(field1) as maxvalue from table1 N)b.$aC
最小:select min(field1) as minvalue from table1 yJGM"$
l=?G"1
5
Yf
T
)Me$BK>
11、说明:几个高级查询运算词 TSHQ>kP
m C&*K
\C.s%m
A: UNION 运算符 w5tcO%+k1
UNION 运算符通过组合其他两个结果表(例如 TABLE1 和 TABLE2)并消去表中任何重复行而派生出一个结果表。当 ALL 随 UNION 一起使用时(即 UNION ALL),不消除重复行。两种情况下,派生表的每一行不是来自 TABLE1 就是来自 TABLE2。 qKL
mL2O
B: EXCEPT 运算符 N56/\1R
EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。当 ALL 随 EXCEPT 一起使用时 (EXCEPT ALL),不消除重复行。 \c.MIDp"
C: INTERSECT 运算符 "g>, X[g
INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。当 ALL 随 INTERSECT 一起使用时 (INTERSECT ALL),不消除重复行。 )T26cT$
注:使用运算词的几个查询结果行必须是一致的。 wtpz ef=
12、说明:使用外连接 jizp\%W+
A、left outer join: }Uc)iNU
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。 >p|tIST
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 mcFJ__3MAV
B:right outer join: x\MzMQ#Bf
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。 xgV(0H}Mf
C:full outer join: 0.}WZAYy~
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。 ygn]f*;?kw
/a:sWmxMT
98x&2(N
二、提升 >p;cbp[ht
1、说明:复制表(只复制结构,源表名:a 新表名:b) (Access可用) #)hJ.0~3
法一:select * into b from a where 1<>1 Bp>Z?"hTe
法二:select top 0 * into b from a (viGL|Ogn
2、说明:拷贝表(拷贝数据,源表名:a 目标表名:b) (Access可用) bw& U[|A0%
insert into b(a, b, c) select d,e,f from b; @K:TGo,%I
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) Q5~Y;0'
insert into b(a, b, c) select d,e,f from b in '具体数据库' where 条件 D?:AHj%gW
例子:..from b in '"&Server.MapPath(".")&"\data.mdb" &"' where.. ? <"H Io
4、说明:子查询(表名1:a 表名2:b) s2rwFj8 |
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) G34fxhh
5、说明:显示文章、提交人和最后回复时间 krI@N}OU
select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b o@!Uds0
6、说明:外连接查询(表名1:a 表名2:b) EmO{lCENk
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c @0{vA\
7、说明:在线视图查询(表名1:a ) =2rkaBFC
select * from (SELECT a,b,c FROM a) T where t.a > 1; 1?}5.*j<
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|}p3-z|Y
select * from table1 where time between time1 and time2 RC>79e/u<
select a,b,c, from table1 where a not between 数值1 and 数值2 G&2`c\u{
9、说明:in 的使用方法 ;H;c Sn5uL
select * from table1 where a [not] in ('值1','值2','值4','值6') RAps`)OR?
10、说明:两张关联表,删除主表中已经在副表中没有的信息 0l&#%wmJ,
delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 ) ZIo%(IT!c
11、说明:四表联查问题: c&AJFED]<
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 ..... ?1kXV n$
12、说明:日程安排提前五分钟提醒 xYUC|c1Q9
SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5 X zF-g*e
13、说明:一条sql 语句搞定数据库分页 k9Xv@v
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 F&= X/
14、说明:前10条记录 ;:5Ahfo \
select top 10 * form table1 where 范围 _)U[c;^6
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.) ]6BV`r]
select a,b,c from tablename ta where a=(select max(a) from tablename tb where tb.b=ta.b) ^;@Q3~DpP%
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 f;7I{Z\<
(select a from tableA ) except (select a from tableB) except (select a from tableC) NplWF\5y
17、说明:随机取出10条数据 y/(60H,{{
select top 10 * from tablename order by newid() ;VI/iwg
18、说明:随机选择记录 mufJ@Y S#
select newid() `: R7jf
19、说明:删除重复记录 7I0[Ii
Delete from tablename where id not in (select max(id) from tablename group by col1,col2,...) Z>t,B%v
20、说明:列出数据库里所有的表名 w#Di
select name from sysobjects where type='U' `BOG e;pl
21、说明:列出表里的所有的 z&a>cjt_;
select name from syscolumns where id=object_id('TableName') n#Y=y#
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。 %{*A@jQsg
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 -m"9v%>Y
显示结果: 2:4:Q[{A
type vender pcs JsZLBq*lP
电脑 A 1 o$%I{}9x
电脑 A 1 P/e6b
.M
光盘 B 2 gXP)YN
光盘 A 2 aR0'$*3E
手机 B 3 M8p6f)l3
手机 C 3 Y;dQLZCC
23、说明:初始化表table1 eF%>5
TRUNCATE TABLE table1 cFF'ygJ/
24、说明:选择从10到15的记录 ys~oJb~
select top 5 * from (select top 15 * from table order by id asc) table_别名 order by id desc ZFH;
94CHxv
#i1z&b#@
yy( .|
三、技巧 a2!;$B%
1、1=1,1=2的使用,在SQL语句组合时用的较多 CL)*cu6zG
"where 1=1" 是表示选择全部 "where 1=2"全部不选, N" =$S|Gs
如: 9-(
\\$%
if @strWhere !='' BdQ/kXZu+
begin 3UX/
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where ' + @strWhere 4?2$~\
x
end }3DZ`8u
else abgAUg)
begin X<*-d6?gD`
set @strSQL = 'select count(*) as Total from [' + @tblName + ']' L63B# H"
end M?QK4Zxb6U
我们可以直接写成 |q+dTy_n
set @strSQL = 'select count(*) as Total from [' + @tblName + '] where 1=1 安定 '+ @strWhere |[B JZ
2、收缩数据库 6Ex16
--重建索引 f(Uo?_as
DBCC REINDEX ];63QJU
DBCC INDEXDEFRAG 'n dXM
--收缩数据和日志 Fd(o8z8Q
DBCC SHRINKDB %~$coZY^
DBCC SHRINKFILE kx.8VUoM
V
3、压缩数据库 A/A;'9
dbcc shrinkdatabase(dbname) +{dJGPoY]p
4、转移数据库给新用户以已存在用户权限 T_NN.Ol
exec sp_change_users_login 'update_one','newname','oldname' qvN`46c
go aWTvowA
5、检查备份集 Hph$Z1{
RESTORE VERIFYONLY from disk='E:\dvbbs.bak' k0^t$J
W
6、修复数据库 P3op1/Np
ALTER DATABASE [dvbbs] SET SINGLE_USER cf{rK`Ff^
GO IQNvhl.{
DBCC CHECKDB('dvbbs',repair_allow_data_loss) WITH TABLOCK cI/Puh^3
GO r'E|6_0
ALTER DATABASE [dvbbs] SET MULTI_USER mi&mQQ
GO f~-qjEWm
7、日志清除 X*QQVj
SET NOCOUNT ON 2Cgq&\wS
DECLARE @LogicalFileName sysname, NS3qNj
@MaxMinutes INT, 1k dQh&~G
@NewSize INT 1h,m
USE tablename -- 要操作的数据库名 t*dd/a
SELECT @LogicalFileName = 'tablename_log', -- 日志文件名 d:{#Dk#
@MaxMinutes = 10, -- Limit on time allowed to wrap log. [+.P'6/[$R
@NewSize = 1 -- 你想设定的日志文件的大小(M) }h=}!R'm
-- Setup / initialize >Nr~7s
DECLARE @OriginalSize int 1P6!E*z\
SELECT @OriginalSize = size vL
]z3
FROM sysfiles -?Kd[Ma
WHERE name = @LogicalFileName K^f&+`v6_
SELECT 'Original Size of ' + db_name() + ' LOG is ' + ]rMHO
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' + S>nf]J`
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB'
B +<i=w
FROM sysfiles gWLhO|y
WHERE name = @LogicalFileName G Ebm$\
CREATE TABLE DummyTrans 5ji#rIAhxh
(DummyColumn char (8000) not null) m!LJK`gA
DECLARE @Counter INT, W)p?cK`
@StartTime DATETIME, hreG5g9{
@TruncLog VARCHAR(255) 2{oU5e
SELECT @StartTime = GETDATE(), k+;XQEH
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY' 8;GuJP\
DBCC SHRINKFILE (@LogicalFileName, @NewSize) ibL
EXEC (@TruncLog) aYrbB#
-- Wrap the log if necessary. GS&iSjw
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired *)xjMTJ%
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) W0;MGBfb
AND (@OriginalSize * 8 /1024) > @NewSize (_Ky'.
BEGIN -- Outer loop. 1!p7N$QR
SELECT @Counter = 0 4KnrQ-D
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000)) JS#AoPWA
BEGIN -- update G/y;o3/[Z
INSERT DummyTrans VALUES ('Fill Log') E;-*LT&{
DELETE DummyTrans s^zX9IVnp
SELECT @Counter = @Counter + 1 3 Xl!Z^W
END :{'%I#k2
EXEC (@TruncLog) .X;DI<K
END Qoom[@$
SELECT 'Final Size of ' + db_name() + ' LOG is ' + 6u[
B}%l
CONVERT(VARCHAR(30),size) + ' 8K pages or ' + 07#e{
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB' ds
"N*\.
FROM sysfiles 9D,/SZ-v
WHERE name = @LogicalFileName rJw
Ws
DROP TABLE DummyTrans U])$#/ v
SET NOCOUNT OFF vHM,_I{
8、说明:更改某个表 s~n@|m9k
exec sp_changeobjectowner 'tablename','dbo' 4ztU) 1
9、存储更改全部表 \Jm^XXgS
CREATE PROCEDURE dbo.User_ChangeObjectOwnerBatch >}) W5Y+
@OldOwner as NVARCHAR(128), z 8y.@<6
@NewOwner as NVARCHAR(128) Xcw6mpLt
AS AEE&{_[S
DECLARE @Name as NVARCHAR(128) }zyh!
DECLARE @Owner as NVARCHAR(128) L yNLz
m5
DECLARE @OwnerName as NVARCHAR(128) 7x//4G
DECLARE curObject CURSOR FOR $ )orXe|
select 'Name' = name, )Nnrsa
'Owner' = user_name(uid) xjH({(/B>a
from sysobjects 0.z\YTZ9
where user_name(uid)=@OldOwner MNu\=p\Eq
order by name T))F
r:
OPEN curObject eiJ~1HX)
FETCH NEXT FROM curObject INTO @Name, @Owner +Z1y1%a
WHILE(@@FETCH_STATUS=0) 9*;OHoD h
BEGIN 3fd?xhWbN
if @Owner=@OldOwner RZbiiMC>
begin *RJiHcII
set @OwnerName = @OldOwner + '.' + rtrim(@Name) ~jDf,a2
exec sp_changeobjectowner @OwnerName, @NewOwner 5h@5.-}
end _qvzZ6
-- select @name,@NewOwner,@OldOwner Sgq" 3(+%,
FETCH NEXT FROM curObject INTO @Name, @Owner |DkK7gw
END M&J$9X
close curObject 'h3yxf}\
deallocate curObject ?~=5x
GO HC(7,3
10、SQL SERVER中直接循环写入数据 <Wa7$ h F
declare @i int \Y^GA;AMQQ
set @i=1 "a=dx|
Z
while @i<30 6S&OE k
begin DW>|'w %
insert into test (userid) values(@i) =cWg39$(I
set @i=@i+1 E@CK.-N|
end EPd
小记存储过程中经常用到的本周,本月,本年函数 0;Z] vl/|
Dateadd(wk,datediff(wk,0,getdate()),-1) `L7Cf&W\l8
Dateadd(wk,datediff(wk,0,getdate()),6) |{9&!=/qf
Dateadd(mm,datediff(mm,0,getdate()),0) }II)<g'
Dateadd(ms,-3,dateadd(mm,datediff(m,0,getdate())+1,0)) SmCtwcB1
Dateadd(yy,datediff(yy,0,getdate()),0) 6L, "gF<n
Dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0)) s4vj
上面的SQL代码只是一个时间段 nXAGwU8a
Dateadd(wk,datediff(wk,0,getdate()),-1) bmI6OIWl
Dateadd(wk,datediff(wk,0,getdate()),6) bu,xIT ^
就是表示本周时间段. a+,zXJQYq
下面的SQL的条件部分,就是查询时间段在本周范围内的: :b"&Rc&s.
Where Time BETWEEN Dateadd(wk,datediff(wk,0,getdate()),-1) AND Dateadd(wk,datediff(wk,0,getdate()),6) Hh`HMa'q
而在存储过程中 \W+Hzf]
W#
select @begintime = Dateadd(wk,datediff(wk,0,getdate()),-1) :@#6]W
select @endtime = Dateadd(wk,datediff(wk,0,getdate()),6) OCv,EZ