Ò׽ؽØÍ¼Èí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

sqlÌæ»»Óï¾ä

--·Ö½â×Ö·û´®°üº¬µÄÐÅÏ¢ÖµºóÈ»ºóºÏ²¢µ½ÁíÍâÒ»±íµÄÐÅÏ¢
--(°®Ð¾õÂÞ.ع»ª(Ê®°ËÄê·çÓê,ÊØµÃ±ùɽѩÁ«»¨¿ª)  2007-12-23  ¹ã¶«ÉîÛÚ)
/*ÎÊÌâÃèÊö
tba
ID  classid   name
1     1,2,3   Î÷·þ
2     2,3     ÖÐɽװ
3     1,3     Ãû¿ã
tbb
id   classname
1     Ò·þ
2     ÉÏÒÂ
3     ¿ã×Ó
ÎҵõĽá¹ûÊÇ
id   classname            name
1     Ò·þ,ÉÏÒÂ,¿ã×Ó      Î÷·þ
2     ÉÏÒ£¬¿ã×Ó          ÖÐɽװ
3     Ò·þ£¬¿ã×Ó          Ãû¿ã
*/
-----------------------------------------------------
--sql server 2000ÖеÄд·¨
create table tba(ID int,classid varchar(20),name varchar(10))
insert into tba values(1,'1,2,3','Î÷·þ')
insert into tba values(2,'2,3'  ,'ÖÐɽװ')
insert into tba values(3,'1,3'  ,'Ãû¿ã')
create table tbb(ID varchar(10), classname varchar(10))
insert into tbb values('1','Ò·þ')
insert into tbb values('2','ÉÏÒÂ')
insert into tbb values('3','¿ã×Ó')
go
--µÚ1ÖÖ·½·¨£¬´´½¨º¯ÊýÀ´ÏÔʾ
create function f_hb(@id varchar(10))
returns varchar(1000)
as
begin
  declare @str varchar(1000)
  set @str=''
  select @str=@str+','+[classname] from tbb where charindex(','+cast(id as varchar)+',',','+@id+',')>0
  return stuff(@str,1,1,'')
end
go
select id,classid=dbo.f_hb(classid),name from tba
drop function f_hb
/*
id          classid       name      
----------- ------------- ----------
1           Ò·þ,ÉÏÒÂ,¿ã×Ó Î÷·þ
2   &


Ïà¹ØÎĵµ£º

SQL²âÊÔ ½»¼¯¡¢²¢¼¯¡¢²î¼¯¡¢µÑ¿¨¶û»ý

²¢¼¯:
ʹÓà UNION ÔËËã·û×éºÏ¶à¸ö½á¹û
SELECT name,num from Table1
UNION
SELECT name,num from Table2
×¢Ò⣺²éѯµÄ×ֶθöÊý±ØÐëÏàͬ£¬Table2µÄ×Ö¶ÎÀàÐÍÒª¸úTable1µÄÏàͬ.
Èç¹ûʹÓà UNION ÔËËã·û£¬ÄÇôµ¥¶ÀµÄ SELECT Óï¾ä²»Äܰüº¬Æä×Ô¼ºµÄ ORDER BY »ò COMPUTE ×Ӿ䡣ֻÄÜÔÚ×îºóÒ»¸ö SELECT Óï¾äµÄºóÃæÊ¹ÓÃÒ»¸ö ORD ......

ADO.net£¬Linq to SQLºÍEntity FrameworkÐÔÄÜʵ²â·ÖÎö


ADO.net£¬Linq to SQLºÍEntity FrameworkÐÔÄÜʵ²â·ÖÎö
¡¡¡¡×î½üÎĵµÐ´Á˲»ÉÙ£¬µ¼ÖÂWordºÍExcelµÄʹÓÃÄÜÁ¦·ÉÒ»°ã³É³¤¡£¿¼Âǵ½ÏîÄ¿ÖжÁдÊý¾Ý¿âµÄ·½·¨´æÔÚЧÂʲ»¸ß£¬ÒÔÖÂÓ°ÏìÓû§ÌåÑéµÄÎÊÌ⣬¾ö¶¨²âÊÔÒ»ÏÂMicrosoftÐÂÍÆÐеÄLinqºÍEFÄܲ»ÄÜÔÚЧÂÊÉÏÓÐËù¸Ä½ø¡£
¡¡¡¡²âÊÔ»·¾³µ±È»¾ÍÊÇÎÒÕą̂±Ê¼Ç±¾ÁË£¬ÊÜÏÞÓëÓ²ÅÌתËÙ£¬ÔËÐÐÆð ......

Êý¾Ý¿â×é¼þ Hxj.Data £¨Ê®£© £¨Êä³ö×é¼þÖ´ÐеÄsql£©

Ç°ÃæÓÐTXÁôÑÔÎÊ·ÖÒ³µÄsqlÊÇÔõôÑùµÄ£¬¿´ÍêÕâÆªÄãÒ²¾ÍÖªµÀÁË¡£ ×é¼þ¿ÉÒÔÊä³öÖ´ÐеÄsql£¬·½±ã²é¿´sqlÉú³ÉµÄÓï¾äÊÇ·ñÓÐÎÊÌâ¡£ ͨ¹ý×¢²áʼþÀ´Êä³ösql DbSession.Default.RegisterSqlLogger(database_OnLog);
 
private string sql;
void database_OnLog(string logMsg)
{
//±£´æÖ´ÐеÄDbCommand (sqlÓï ......

sql group by Óë havingµÄÓ÷¨

1. GROUP BY ÊÇ·Ö×é²éѯ, Ò»°ã GROUP BY ÊǺ;ۺϺ¯ÊýÅäºÏʹÓÃ
group by ÓÐÒ»¸öÔ­Ôò,¾ÍÊÇ select ºóÃæµÄËùÓÐÁÐÖÐ,ûÓÐʹÓþۺϺ¯ÊýµÄÁÐ,±ØÐë³öÏÖÔÚ group by ºóÃæ£¨ÖØÒª£©
ÀýÈç,ÓÐÈçÏÂÊý¾Ý¿â±í£º
A    B
1    abc
1    bcd
1    asdfg
 Èç¹ûÓÐÈ ......

Ôõô´Óoracleͨ¹ýodbc ºÍsqlµÃµ½mysql

 oracleµÄodbcÍø¹Ø£¨gateway£©¼¸ºõÌṩһ¸öÎÞÏßµÄÊý¾ÝÕûºÏƽ̨£¬ÔÚoracleºÍÆäËüRDBMSÖ®¼ä£¬ÎÒÔÚÕâ²»Ïë˵ËüµÄ£¬²Ù×÷£¬ÏÞÖÆÒÔ¼°Ïà¹ØÐÔ£¬Ëü½â¾öÁËÒ»¸öСÎÊÌ⣬°ÑËü½¨Á¢ÆðÀ´ÄãÄÜ£¬ÀýÈ磬´´½¨Ò»¸ö database link ÔÚoracle ºÍoracleÖ®¼ä£¬±Ï¾¹£¬ÕâÑù²»ÊǺܺÃô£¬ÀýÈçÄãÄÜÔËÐÐÏÂÃæµÄsqlÓï¾ä£¬
select o.col1, m.col1 from or ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ