SQL·ÖÒ³Óï¾ä
±àÂë¹ý³ÌÖÐÓöµ½µÄSQL·ÖÒ³Çé¿ö£¬×ܽ᣺
´ÓÊý¾Ý¿â±íÖеÚMÌõ¼Ç¼¿ªÊ¼¼ìË÷NÌõ¼Ç¼
MySQL£º
ÏȲéѯ·ÖÒ³£¬È»ºóÅÅÐò£º
select * from (select * from student limit 5,2) pageTable order by id desc ;
ÏÈÅÅÐò£¬È»ºó²éѯ·ÖÒ³£ºselect * from student order by id desc limit 5,2 ;
Oracle£º
SELECT * from (SELECT ROWNUM r,t1.* from ±íÃû³Æ t1 where rownum < M + N) pageTable where t2.r >= M;
SELECT * from (SELECT ROWNUM r,s.* from student s where rownum < 7) pageTable where t2.r >= 5
Ïà¹ØÎĵµ£º
declare @t varchar(255),@c varchar(255)
declare table_cursor cursor for select a.name,b.name
from sysobjects a,syscolumns b ,systypes c
where a.id=b.id and a.xtype='u'&n ......
´ó¼Ò¶¼ÔÚÌÖÂÛ¹ØÓÚÊý¾Ý¿âÓÅ»¯·½ÃæµÄ¶«¶«£¬¸ÕºÃ²ÎÓ뿪·¢ÁËÒ»¸öÊý¾Ý²Ö¿â·½ÃæµÄÏîÄ¿£¬ÒÔϵÄÒ»µã¶«Î÷ËãÊÇÊý¾Ý¿âÓÅ»¯·½ÃæµÄѧϰ+ʵսµÄһЩÐĵÃÌå»áÁË£¬ÄóöÀ´´ó¼Ò¹²Ïí¡£»¶ÓÅúÆÀÖ¸Õý°¢£¡
SQLÓï¾ä£º
ÊǶÔÊý¾Ý¿â(Êý¾Ý)½øÐвÙ×÷µÄΩһ;¾¶£»
ÏûºÄÁË70%~90%µÄÊý¾Ý¿â×ÊÔ´£»¶ÀÁ¢ÓÚ³ÌÐòÉè¼ÆÂß¼£¬Ïà¶ÔÓÚ¶Ô³ÌÐòÔ´´úÂëµÄÓÅ»¯£¬¶ÔSQ ......
¹¤×÷ÖÐÅöµ½µÄС¼¼ÇÉ£¬±ÈÈç˵ҪÓÃÊý¾Ý±íÀïÈ¡³ö×¢²áÓû§µÄ×ÊÁÏ£¬ÐÔ±ðΪ1ÔòÏÔʾΪÄÐÉú£»ÐÔ±ðΪ2ÔòÏÔʾΪŮÉú£»ÒÔǰ¶¼ÊÇ´Ó±íÀïÈ¡³öÊý¾Ý£¬È»ºóÔÙÓôúÂë½øÐÐÅжϣ¬Îª1ÔòÏÔʾΪÄÐÉú£»Îª2ÔòÏÔʾΪŮÉú£»Æäʵµ¥ÓÃSQLÓï¾ä¾Í¿ÉÒÔ×öµ½£¬ÈçÏ£º
Ö±½ÓʹÓÃcase when else Óï¾ä
Case¾ßÓÐÁ½ÖÖ¸ñʽ¡£¼òµ¥Caseº¯ÊýºÍCaseË ......
Select TOP N * from TABLE Order By NewID()
--Access£º
Select TOP N * from TABLE Order By Rnd(ID)
Rnd(ID) ÆäÖеÄIDÊÇ×Ô¶¯±àºÅ×ֶΣ¬¿ÉÒÔÀûÓÃÆäËûÈκÎÊýÖµÀ´Íê³É£¬±ÈÈçÓÃÐÕÃû×Ö¶Î(UserName)
Selec ......
1.ÔÚmssql´´½¨´æ´¢¹ý³Ì,ÔÚdb->´æ´¢¹ý³Ì->н¨´æ´¢¹ý³Ì(ÓÒ¼ü)
CREATE PROCEDURE user_logon_check @username varchar(45),@userpsw varchar(45)
AS
select * from users where UserName = @username and PasswordCode = @userpsw
return 10
GO
2.ÔÚmysql´´½¨´æ´¢¹ý³Ì,ʹÓÃMysql Query Browser,ÔÚdb->±í ......