说明Q复制表(只复制结?源表名：(x)a 新表名：(x)b)
select * into b from a where 1<>1
说明Q拷贝表(拯数据,源表名：(x)a 目标表名Qb)
insert into b(a, b, c) select d,e,f from b;
说明Q显C文章、提交h和最后回复时?br />select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b
说明Q外q接查询(表名1Qa 表名2Qb)
select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c
说明Q日E安排提前五分钟提醒
select * from 日程安排 where datediff('minute',f开始时?getdate())>5
说明Q两张关联表Q删除主表中已经在副表中没有的信?br />delete from info where not exists ( select * from infobz where info.infid=infobz.infid )
说明Q?-
SQL:
SELECT A.NUM, A.NAME, B.UPD_DATE, B.PREV_UPD_DATE
FROM TABLE1,
(SELECT X.NUM, X.UPD_DATE, Y.UPD_DATE PREV_UPD_DATE
FROM (SELECT NUM, UPD_DATE, INBOUND_QTY, STOCK_ONHAND
FROM TABLE2
WHERE TO_CHAR(UPD_DATE,'YYYY/MM') = TO_CHAR(SYSDATE, 'YYYY/MM')) X,
(SELECT NUM, UPD_DATE, STOCK_ONHAND
FROM TABLE2
WHERE TO_CHAR(UPD_DATE,'YYYY/MM') =
TO_CHAR(TO_DATE(TO_CHAR(SYSDATE, 'YYYY/MM') || '/01','YYYY/MM/DD') - 1, 'YYYY/MM') ) Y,
WHERE X.NUM = Y.NUM Q?Q?
AND X.INBOUND_QTY + NVL(Y.STOCK_ONHAND,0) <> X.STOCK_ONHAND ) B
WHERE A.NUM = B.NUM
说明Q?-
select * from studentinfo where not exists(select * from student where studentinfo.id=student.id) and pdU?'"&strdepartmentname&"' and 专业名称='"&strprofessionname&"' order by 性别,生源?高考Ll?br />
从数据库中去一q的各单位电(sh)话费l计(?sh)话费定额贺电(sh)化肥清单两个表来源Q?
SELECT a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy') AS telyear,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '01', a.factration)) AS JAN,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '02', a.factration)) AS FRI,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '03', a.factration)) AS MAR,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '04', a.factration)) AS APR,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '05', a.factration)) AS MAY,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '06', a.factration)) AS JUE,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '07', a.factration)) AS JUL,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '08', a.factration)) AS AGU,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '09', a.factration)) AS SEP,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '10', a.factration)) AS OCT,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '11', a.factration)) AS NOV,
SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '12', a.factration)) AS DEC
FROM (SELECT a.userper, a.tel, a.standfee, b.telfeedate, b.factration
FROM TELFEESTAND a, TELFEE b
WHERE a.tel = b.telfax) a
GROUP BY a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy')
说明Q四表联查问?br />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 .....
说明Q得到表中最的未用的ID?br />
SELECT (CASE WHEN EXISTS(SELECT * FROM Handle b WHERE b.HandleID = 1) THEN MIN(HandleID) + 1 ELSE 1 END) as HandleID FROM Handle WHERE NOT HandleID IN (SELECT a.HandleID - 1 FROM Handle a)
一个SQL语句的问?行列转换
select * from v_temp
上面的视囄果如?
user_name role_name
-------------------------
pȝ理?理?
feng 理?
feng 一般用?
test 一般用?
xl果变成q样:
user_name role_name
---------------------------
pȝ理?理?
feng 理?一般用?
test 一般用?br />===================
create table a_test(name varchar(20),role2 varchar(20))
insert into a_test values('?,'理?)
insert into a_test values('?,'理?)
insert into a_test values('?,'一般用?)
insert into a_test values('?,'一般用?)
create function join_str(@content varchar(100))
returns varchar(2000)
as
begin
declare @str varchar(2000)
set @str=''
select @str=@str+','+rtrim(role2) from a_test where [name]=@content
select @str=right(@str,len(@str)-1)
return @str
end
go
--调用Q?br />select [name],dbo.join_str([name]) role2 from a_test group by [name]
--select distinct name,dbo.uf_test(name) from a_test
快速比较结构相同的两表
l构相同的两表，一表有记录3万条左右Q一表有记录2万条左右Q我怎样快速查找两表的不同记录Q?br />============================
l你一个测试方法，从northwind中的orders表取数据?br />select * into n1 from orders
select * into n2 from orders
select * from n1
select * from n2
--d主键Q然后修改n1中若q字D늚若干?br />alter table n1 add constraint pk_n1_id primary key (OrderID)
alter table n2 add constraint pk_n2_id primary key (OrderID)
select OrderID from (select * from n1 union select * from n2) a group by OrderID having count(*) > 1
应该可以Q而且不同的记录的ID昄出来?br />下面的适用于双方记录一L(fng)情况Q?br />
select * from n1 where orderid in (select OrderID from (select * from n1 union select * from n2) a group by OrderID having count(*) > 1)
至于双方互不存在的记录是比较好处理的
--删除n1,n2中若q条记录
delete from n1 where orderID in ('10728','10730')
delete from n2 where orderID in ('11000','11001')
--*************************************************************
-- 双方都有该记录却不完全相?br />select * from n1 where orderid in(select OrderID from (select * from n1 union select * from n2) a group by OrderID having count(*) > 1)
union
--n2中存在但在n1中不存的?0728,10730
select * from n1 where OrderID not in (select OrderID from n2)
union
--n1中存在但在n2中不存的?1000,11001
select * from n2 where OrderID not in (select OrderID from n1)
四种Ҏ(gu)取表里n到m条纪录：(x)
1.
select top m * into 临时?或表变量) from tablename order by columnname -- top mW插?br />set rowcount n
select * from 表变?order by columnname desc
2.
select top n * from (select top m * from tablename order by columnname) a order by columnname desc
3.如果tablename里没有其他identity列，那么Q?br />select identity(int) id0,* into #temp from tablename
取n到m条的语句为：(x)
select * from #temp where id0 >=n and id0 <= m
如果你在执行select identity(int) id0,* into #temp from tablenameq条语句的时候报?那是因ؓ(f)你的DB中间的select into/bulkcopy属性没有打开要先执行Q?br />exec sp_dboption 你的DB名字,'select into/bulkcopy',true
4.如果表里有identity属性，那么单：(x)
select * from tablename where identitycol between n and m
如何删除一个表中重复的记录Q?br />create table a_dist(id int,name varchar(20))
insert into a_dist values(1,'abc')
insert into a_dist values(1,'abc')
insert into a_dist values(1,'abc')
insert into a_dist values(1,'abc')
exec up_distinct 'a_dist','id'
select * from a_dist
create procedure up_distinct(@t_name varchar(30),@f_key varchar(30))
--f_key表示是分l字D﹐即主键字D?br />as
begin
declare @max integer,@id varchar(30) ,@sql varchar(7999) ,@type integer
select @sql = 'declare cur_rows cursor for select '+@f_key+' ,count(*) from ' +@t_name +' group by ' +@f_key +' having count(*) > 1'
exec(@sql)
open cur_rows
fetch cur_rows into @id,@max
while @@fetch_status=0
begin
select @max = @max -1
set rowcount @max
select @type = xtype from syscolumns where id=object_id(@t_name) and name=@f_key
if @type=56
select @sql = 'delete from '+@t_name+' where ' + @f_key+' = '+ @id
if @type=167
select @sql = 'delete from '+@t_name+' where ' + @f_key+' = '+''''+ @id +''''
exec(@sql)
fetch cur_rows into @id,@max
end
close cur_rows
deallocate cur_rows
set rowcount 0
end
select * from systypes
select * from syscolumns where id = object_id('a_dist')
查询数据的最大排序问题（只能用一条语句写Q?
CREATE TABLE hard (qu char (11) ,co char (11) ,je numeric(3, 0))
insert into hard values ('A','1',3)
insert into hard values ('A','2',4)
insert into hard values ('A','4',2)
insert into hard values ('A','6',9)
insert into hard values ('B','1',4)
insert into hard values ('B','2',5)
insert into hard values ('B','3',6)
insert into hard values ('C','3',4)
insert into hard values ('C','6',7)
insert into hard values ('C','2',3)
要求查询出来的结果如下：(x)
qu co je
----------- ----------- -----
A 6 9
A 2 4
B 3 6
B 2 5
C 6 7
C 3 4
是要按qu分组Q每l中取je最大的?位！Q?br />而且只能用一句sql语句Q！Q?br />select * from hard a where je in (select top 2 je from hard b where a.qu=b.qu order by je)
求删除重复记录的sql语句Q?
怎样把具有相同字D늚U录删除Q只留下一条?br />例如Q表test里有id,name字段
如果有name相同的记?只留下一条，其余的删除?br />name的内容不定，相同的记录数不定?br />有没有这L(fng)sql语句Q?br />==============================
A:一个完整的解决Ҏ(gu)Q?br />
重复的记录记入temp1?
select [标志字段id],count(*) into temp1 from [表名]
group by [标志字段id]
having count(*)>1
2、将不重复的记录记入temp1?
insert temp1 select [标志字段id],count(*) from [表名] group by [标志字段id] having count(*)=1
3、作一个包含所有不重复记录的表Q?br />select * into temp2 from [表名] where 标志字段id in(select 标志字段id from temp1)
4、删除重复表:
delete [表名]
5、恢复表Q?br />insert [表名] select * from temp2
6、删除(f)时表:
drop table temp1
drop table temp2
================================
B:
create table a_dist(id int,name varchar(20))
insert into a_dist values(1,'abc')
insert into a_dist values(1,'abc')
insert into a_dist values(1,'abc')
insert into a_dist values(1,'abc')
exec up_distinct 'a_dist','id'
select * from a_dist
create procedure up_distinct(@t_name varchar(30),@f_key varchar(30))
--f_key表示是分l字D﹐即主键字D?br />as
begin
declare @max integer,@id varchar(30) ,@sql varchar(7999) ,@type integer
select @sql = 'declare cur_rows cursor for select '+@f_key+' ,count(*) from ' +@t_name +' group by ' +@f_key +' having count(*) > 1'
exec(@sql)
open cur_rows
fetch cur_rows into @id,@max
while @@fetch_status=0
begin
select @max = @max -1
set rowcount @max
select @type = xtype from syscolumns where id=object_id(@t_name) and name=@f_key
if @type=56
select @sql = 'delete from '+@t_name+' where ' + @f_key+' = '+ @id
if @type=167
select @sql = 'delete from '+@t_name+' where ' + @f_key+' = '+''''+ @id +''''
exec(@sql)
fetch cur_rows into @id,@max
end
close cur_rows
deallocate cur_rows
set rowcount 0
end
select * from systypes
select * from syscolumns where id = object_id('a_dist')
行列转换--普?
假设有张学生成W?CJ)如下
Name Subject Result
张三 语文 80
张三 数学 90
张三 物理 85
李四 语文 85
李四 数学 92
李四 物理 82
惛_?
姓名 语文 数学 物理
张三 80 90 85
李四 85 92 82
declare @sql varchar(4000)
set @sql = 'select Name'
select @sql = @sql + ',sum(case Subject when '''+Subject+''' then Result end) ['+Subject+']'
from (select distinct Subject from CJ) as a
select @sql = @sql+' from test group by name'
exec(@sql)
行列转换--合ƈ
有表A,
id pid
1 1
1 2
1 3
2 1
2 2
3 1
如何化成表B:
id pid
1 1,2,3
2 1,2
3 1
创徏一个合q的函数
create function fmerg(@id int)
returns varchar(8000)
as
begin
declare @str varchar(8000)
set @str=''
select @str=@str+','+cast(pid as varchar) from 表A where id=@id
set @str=right(@str,len(@str)-1)
return(@str)
End
go
--调用自定义函数得到结?
select distinct id,dbo.fmerg(id) from 表A
如何取得一个数据表的所有列?
Ҏ(gu)如下Q先从SYSTEMOBJECTpȝ表中取得数据表的SYSTEMID,然后再SYSCOLUMN表中取得该数据表的所有列名?
SQL语句如下Q?
declare @objid int,@objname char(40)
set @objname = 'tablename'
select @objid = id from sysobjects where id = object_id(@objname)
select 'Column_name' = name from syscolumns where id = @objid order by colid
?br />
SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME ='users'
通过SQL语句来更改用L(fng)密码
修改别h?需要sysadmin role
EXEC sp_password NULL, 'newpassword', 'User'
如果帐号为SA执行EXEC sp_password NULL, 'newpassword', sa
怎么判断Z个表的哪些字D不允许为空Q?
select COLUMN_NAME from INFORMATION_SCHEMA.COLUMNS where IS_NULLABLE='NO' and TABLE_NAME=tablename
如何在数据库里找到含有相同字D늚表？
a. 查已知列名的情况
SELECT b.name as TableName,a.name as columnname
From syscolumns a INNER JOIN sysobjects b
ON a.id=b.id
AND b.type='U'
AND a.name='你的字段名字'
未知列名查所有在不同表出现过的列?
Select o.name As tablename,s1.name As columnname
From syscolumns s1, sysobjects o
Where s1.id = o.id
And o.type = 'U'
And Exists (
Select 1 From syscolumns s2
Where s1.name = s2.name
And s1.id <> s2.id
)
查询Wxxx行数?
假设id是主键：(x)
select * from (select top xxx * from yourtable) aa where not exists(select 1 from (select top xxx-1 * from yourtable) bb where aa.id=bb.id)
如果使用游标也是可以?
fetch absolute [number] from [cursor_name]
行数为绝对行?
SQL Server日期计算
a. 一个月的第一?
SELECT DATEADD(mm, DATEDIFF(mm,0,getdate()), 0)
b. 本周的星期一
SELECT DATEADD(wk, DATEDIFF(wk,0,getdate()), 0)
c. 一q的W一?
SELECT DATEADD(yy, DATEDIFF(yy,0,getdate()), 0)
d. 季度的第一?
SELECT DATEADD(qq, DATEDIFF(qq,0,getdate()), 0)
e. 上个月的最后一?
SELECT dateadd(ms,-3,DATEADD(mm, DATEDIFF(mm,0,getdate()), 0))
f. d的最后一?
SELECT dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate()), 0))
g. 本月的最后一?
SELECT dateadd(ms,-3,DATEADD(mm, DATEDIFF(m,0,getdate())+1, 0))
h. 本月的第一个星期一
select DATEADD(wk, DATEDIFF(wk,0,
dateadd(dd,6-datepart(day,getdate()),getdate())
), 0)
i. 本年的最后一?
SELECT dateadd(ms,-3,DATEADD(yy, DATEDIFF(yy,0,getdate())+1, 0))?
获取表结构[?'sysobjects' 替换 ?'tablename' 卛_]
SELECT CASE IsNull(I.name, '')
When '' Then ''
Else '*'
End as IsPK,
Object_Name(A.id) as t_name,
A.name as c_name,
IsNull(SubString(M.text, 1, 254), '') as pbc_init,
T.name as F_DataType,
CASE IsNull(TYPEPROPERTY(T.name, 'Scale'), '')
WHEN '' Then Cast(A.prec as varchar)
ELSE Cast(A.prec as varchar) + ',' + Cast(A.scale as varchar)
END as F_Scale,
A.isnullable as F_isNullAble
FROM Syscolumns as A
JOIN Systypes as T
ON (A.xType = T.xUserType AND A.Id = Object_id('sysobjects') )
LEFT JOIN ( SysIndexes as I
JOIN Syscolumns as A1
ON ( I.id = A1.id and A1.id = object_id('sysobjects') and (I.status & 0x800) = 0x800 AND A1.colid <= I.keycnt) )
ON ( A.id = I.id AND A.name = index_col('sysobjects', I.indid, A1.colid) )
LEFT JOIN SysComments as M
ON ( M.id = A.cdefault and ObjectProperty(A.cdefault, 'IsConstraint') = 1 )
ORDER BY A.Colid ASC
提取数据库内所有表的字D详l说明的SQL语句
SELECT
(case when a.colorder=1 then d.name else '' end) N'表名',
a.colorder N'字段序号',
a.name N'字段?,
(case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '?else ''
end) N'标识',
(case when (SELECT count(*)
FROM sysobjects
WHERE (name in
(SELECT name
FROM sysindexes
WHERE (id = a.id) AND (indid in
(SELECT indid
FROM sysindexkeys
WHERE (id = a.id) AND (colid in
(SELECT colid
FROM syscolumns
WHERE (id = a.id) AND (name = a.name))))))) AND
(xtype = 'PK'))>0 then '? else '' end) N'主键',
b.name N'cd',
a.length N'占用字节?,
COLUMNPROPERTY(a.id,a.name,'PRECISION') as N'长度',
isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0) as N'数位数',
(case when a.isnullable=1 then '?else '' end) N'允许I?,
isnull(e.text,'') N'默认?,
isnull(g.[value],'') AS N'字段说明'
FROM syscolumns a
left join systypes b
on a.xtype=b.xusertype
inner join sysobjects d
on a.id=d.id and d.xtype='U' and d.name<>'dtproperties'
left join syscomments e
on a.cdefault=e.id
left join sysproperties g
on a.id=g.id AND a.colid = g.smallid
order by object_name(a.id),a.colorder
快速获取表test的记录L[对大定w表非常有效]
快速获取表test的记录L:
select rows from sysindexes where id = object_id('test') and indid in (0,1)
update 2 set KHXH=(ID+1)\2 2行递增~号
update [23] set id1 = 'No.'+right('00000000'+id,6) where id not like 'No%' //递增
update [23] set id1= 'No.'+right('00000000'+replace(id1,'No.',''),6) //补位递增
delete from [1] where (id%2)=1
奇数
替换表名字段
update [1] set domurl = replace(domurl,'Upload/Imgswf/','Upload/Photo/') where domurl like '%Upload/Imgswf/%'
截位
SELECT LEFT(表名, 5)
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