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 !=''
begin
set @strsql = 'select count(*) as total from [' + @tblname + '] where ' +@strwhere
endelse
begin
set @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 totalfrom [' + @tblname + '] where 1=1
安定 '+ @strwhere
2、收縮資料庫
--重建索引
dbccreindex
dbcc indexdefrag
--收縮資料和日誌
dbccshrinkdb
dbcc shrinkfile
3、壓縮資料庫
dbcc shrinkdatabase(dbname)
4、轉移資料庫給新使用者以已存在使用者許可權
exec sp_change_users_login 'update_one','newname','oldname'
go5、檢查備份集
restore verifyonly fromdisk='e:\dvbbs.bak'
6、修復資料庫
alter database [dvbbs] set single_user
godbcc checkdb('dvbbs',repair_allow_data_loss) with tablock
goalter database [dvbbs] set multi_user
go7、日誌清除
set nocount on
declare @logicalfilename sysname,
@maxminutes int,
@newsize int
usetablename -- 要操作的資料庫名
select @logicalfilename = 'tablename_log', -- 日誌檔名
@maxminutes= 10, -- limit on time allowed to wrap log.
@newsize = 1 -- 你想設定的日誌檔案的大小(m)
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)
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 notexpired
and @originalsize = (select size fromsysfiles 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
endexec (@trunclog)
endselect 'final size of ' + db_name() + ' log is ' +
convert(varchar(30),size) + ' 8k pagesor ' +
convert(varchar(30),(size*8/1024)) +'mb'
from sysfiles
where name = @logicalfilename
drop table dummytrans
set nocount off
8、說明：更改某個表
exec sp_changeobjectowner'tablename','dbo'
9、儲存更改全部表
create proceduredbo.user_changeobjectownerbatch
@oldowner as nvarchar(128),
@newowner as nvarchar(128)
asdeclare@name as nvarchar(128)
declare @owner as nvarchar(128)
declare @ownername as nvarchar(128)
declare curobjectcursor for
select 'name' = name,
'owner' = user_name(uid)
from sysobjects
where user_name(uid)=@oldowner
order by name
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
fetch next fromcurobject into @name, @owner
endclose curobject
deallocate curobject
go10、sql server中直接迴圈寫入資料
declare @i int
set @i=1
while @i<30
begin
insert into test (userid) values(@i)
set @i=@i+1
end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的基礎上，使他們剛好及格:
name score
zhangshan80
lishi 59
wangwu 50
songquan69
while((select
min(score)from tb_table)<60)
begin
updatetb_table set score =score*1.01
wherescore
<60
if (select
min(score) from tb_table)>60
break
else
continue
end
SQL語句經典大全（三）技巧
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 begin set strsql select count as total from tblname where strwhere ende...
SQL語句大全 技巧
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 begin set strsql select count as total from tblname where strwhere ende...
經典SQL語句大全（三）
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 begin set strsql select count as total from tblname where strwhere ende...