一些sql整理

1、通過sql語言查詢表結構：(MSSQL2000中有效)

作用：可以快速生成數據詞典。

SELECT TOP 100 PERCENT c.colid AS 序號, o.name AS 表名, c.name AS 列名,
      t.name AS 類型, c.length AS 長度, c.isnullable AS 允許空,
      CAST(m.[value] AS Varchar(100)) AS 說明
FROM dbo.syscolumns c INNER JOIN
      dbo.sysobjects o ON o.id = c.id AND objectproperty(o.id, N'IsUserTable') = 1 AND
      o.name <> 'dtproperties' INNER JOIN
      dbo.systypes t ON t.xusertype = c.xusertype LEFT OUTER JOIN
      dbo.sysproperties m ON m.id = o.id AND m.smallid = c.colorder
ORDER BY o.name, c.colid

說明：【sysproperties】表 原來【SQL2000】中的表【sysproperties】在【SQL2005】中已經不存在了，被是表【extended_properties】取代了

所以在SQL2005中改成：

SELECT TOP 100 PERCENT c.colid AS 序號, o.name AS 表名, c.name AS 列名,
      t.name AS 類型, c.length AS 長度, c.isnullable AS 允許空,
      CAST(m.[value] AS Varchar(100)) AS 說明
FROM dbo.syscolumns c INNER JOIN
      dbo.sysobjects o ON o.id = c.id AND objectproperty(o.id, N'IsUserTable') = 1 AND
      o.name <> 'dtproperties' INNER JOIN
      dbo.systypes t ON t.xusertype = c.xusertype LEFT OUTER JOIN
      sys.extended_properties m ON m.major_id = o.id AND m.minor_id = c.colorder
ORDER BY o.name, c.colid

2、通過作業定製定期數據庫備份

定期備份數據庫，減少人工操作，但是缺點是隨着時間的增長，不斷生成備份文件，造成文件容量不斷增大，需要定期刪除早期的不需要的備份。可以定製作業定期刪除規定時間內的備份文件。參考之前整理的資料（數據庫日常維護常用的腳本部分收錄）

根據需要修改備份存儲路徑、數據庫名稱、備份名稱；作用備份語句：

declare @filename nvarchar(100);
set @filename='E:\BackUP_data_bak\databaseName_data\databaseName_backup_'
+convert(char(10),getdate(),112)+'.bak' print @filename;
backup database [DatabaseDB]
to disk=@filename with noinit,nounload,name=N'BackUP_databaseName',
noskip,stats=10,noformat;     /*DatabaseDB:要備份的數據庫名稱;BackUPDatabase:備份名稱*/

 3、函數（工作中的需求）

根據給出的字符串得出相應的權重，給出的字符串如：'S41J11G41S21'

執行代碼：

select dbo.fun_GetPrizeValue('S41J11G41S21')

函數代碼：

create function [dbo].[fun_GetPrizeValue](@str varchar(15))
returns float
as
begin
declare @num int,@i int,@value float,@sum float,@m int
set @i=1
set @m=0
set @sum=0
if(@str='') set @num=0
else select @num=len(@str)
while @i<=(@num/3)
begin
select @value=case when substring(@str,@i+@m,2)= 'G2' then 9
when substring(@str,@i+@m,2)='G3' then 0.95
when substring(@str,@i+@m,2)='G4' then 0.8
when substring(@str,@i+@m,2)='S2' then 0.75
when substring(@str,@i+@m,2)='J1' then 0.7
when substring(@str,@i+@m,2)='G1' then 95
when substring(@str,@i+@m,2)='S4' then 0.6
else 0 end
set @sum=@value*convert(int,substring(@str,@i+2+@m,1))+@sum
set @i=@i+1
set @m=@m+2
end
return @sum
end

 4、遞歸查詢

當遇到一個樹狀結構存儲的表時，即，一個表中存在兩個字段：ID，ParentID時，通過給出一個ID，獲得該ID的所有子信息，通過創建存儲過程，並調用存儲過程實現。可根據需要做相應的修改。

存儲過程：

create procedure [dbo].[sp_search](@id int)
as
declare @level int,@cur int
create table #stack
(depth_level int,
tb1_id int
)
create table #tmp
(seq_no int identity(1,1),
org_level int not null,
tb1_id int not null
)
select @level=1
select @cur=@id
insert into #stack(depth_level,tb1_id) select @level,tableNameID from tableName where tablenameID=@id
while (@level>0)
begin
if exists (select * from #stack where depth_level=@level)
begin
set rowcount 1
select @cur=tb1_id from #stack where depth_level=@level
set rowcount 0
insert into #tmp(org_level,tb1_ID)select @level,@cur
delete from #stack where depth_level=@level and tb1_id=@cur
insert into #stack select @level+1,tableNameID from tableName where
tableNameFatherID=@cur and tableNameFatherID<>tableNameID
if @@rowcount>0
select @level=@level+1
end
else
begin
select @level=@level-1
end
end
/*select * from #tmp*/
select * from tableName where tableNameID in (select tb1_id from #tmp)

執行代碼：

exec dbo.sp_search 1

 5、創建數據庫SQL語言

create database DatabaseDB
on primary
(
name='DatabaseDB_Data',--主數據文件的邏輯名
filename='D:\database\DatabaseDB_data.mdf',--主數據文件的物理名
size=10MB,--初始大小
filegrowth=10%--增長率
)
log on
(
name='DatabaseDB_Log',--日誌文件的邏輯名
fileName='D:\database\DatabaseDB_data.ldf',--日誌文件的物理名
size=1MB,
maxsize=20MB,--最大大小
filegrowth=10%
)