ÓйØSQLÖÐÂß¼²éѯ´¦ÀíµÄ¸÷¸ö½×¶Î£¨×Ô¼º¸ãµÄÀý×Ó£¬²»¶ÔµÄ»¶ÓÖ¸ÕýŶ£©
SQL²»Í¬ÓÚÆäËûµÄ±à³ÌÓïÑÔµÄ×î´ó×î´óÌØÕ÷ÓÐ3¸ö°É£¬
Ò»¸öÊÇËüÊÇÃæÏò¼¯ºÏµÄ±à³Ì˼Ï룬µÚ¶þ¸öÊÇÈýÖµÂß¼£¨Õâ¸öºóÃæ»á˵µ½£©£¬»¹ÓÐÒ»¸ö¾ÍÊǽñÌìÖ÷ҪҪ˵µÄ²éÑ¯ÔªËØµÄÂß¼´¦Àí´ÎÐò¡£
Çë¿´Ò»¸ö»ù±¾²éѯµÄÂß¼¹ý³Ì£º
(8) SELECT (9) DISTINCT (11) <TOP_specification> <select_list>
(1) from <left_table>
(3) <join_type> JOIN <right_table>
(2) ON <join_condition>
(4) WHERE <where_condition>
(5) GROUP BY <group_by_list>
(6) WITH {CUBE | ROLLUP}
(7) HAVING <having_condition>
(10) ORDER BY <order_by_list>
´ó¼Ò¿ÉÒÔ¿´µ½ ÕâÀïµÄÔËÐв½Öè²»ÊÇÏñÒ»°ãµÄ±à³Ì Ò»¾ä¾ä´ÓÉÏÍùÏ ËüÊÇÌø¶¯µÄ ÓлîÁ¦µÄ
ÕâÀïÌáǰ˵Ï ÿһ²½¶¼»á²úÉúÒ»¸öÐéÄâµÄ±í£¨Ò²¿ÉÄÜÊÇÓα꣬ÏÂÃæ»áÌáµ½£©£¬×÷ΪÏÂÒ»¸ö²½ÖèµÄÊäÈë¡£´ó¼Ò×îºó¿´µ½µÄ½á¹ûÆäʵ¾ÍÊÇ×îºóÒ»¸öÐéÄâ±íÁË¡£
ºÃÁË£¬ÏÂÃæÎÒ¿ªÊ¼¾ßÌå²ûÊÍÿ¸ö²½Ö裺
²âÊÔ»·¾³£º
--ÌâĿҪÇó£ºÇó³öѧÉú×îµÍ¿ÆÄ¿³É¼¨²»µÍÓÚ90·ÖÇÒÄêÁäÔÚ7ËêÒÔÉϵÄѧÉúÐÕÃû
create table #student(s# int,sname varchar(10),age int)
create table #study (s# int, c# char(1),score int)
insert #student
1,'xiaozhu',10 union all select
2,'xiaomao' ,9union all select
3,'xiaozhe' ,7union all select
4,'xiaophai',8 union all select
5,'xiaoduo',9
insert #study select
1,'A',99 union all select
1,'B',90 union all select
1,'C',99 union all select
2,'A',99 union all select
2,'b',99 union all select
2,'c',98 union all select
3,'A',99 union all select
3,'b',92 union all select
3,'c',91 union all select
3,'d',90 union all select
4,'A',88 union all select
4,'B',96
--SQLÓï¾ä
select top 1 sname,MIN(score) as minsocre
from #student s left outer join #study sc
on s.s#=sc.s#
where age>7
group by sname
having MIN(score)>=90
order by minsocre
/*
sname minsocre
---------- -----------
xiaozhu 90
*/
(1)£ºÖ´Ðеѿ¨¶û»ý£¨CROSS JOIN £©
´ó¼ÒÕâ
ÔÎÄ´«ËÍÃÅ£ºhttp://topic.csdn.net/u/20091010/14/FC7737C1-D60B-43F1-A8B5-A9EEF2DE4426.html
¼ÙÈçÏÖÔÚÓÐÁ½ÕÅ±í£º
1.±ístuinfo
sid sname subs
1 jack |1|2|
2 marry |1|4|
3 tom |3|
2.±ísubinfo
subid subname
1 physics
2 &n ......
“¹¤ÓûÉÆÆäÊ£¬±ØÏÈÀûÆäÆ÷”¡£ÐÅÏ¢¼¼ÊõÔÚÉÌÒµÁìÓòÓ¦ÓõÄ׿Խ³ÉЧÔÚ¾¹ý½ü20ÄêµÄÐÅÏ¢»¯½¨ÉèÒѾ³õ²½ÏÔÏÖ¡£Æóҵͨ¹ýMIS£¨¹ÜÀíÐÅϢϵͳ£©¿ìËÙÊÕ¼¯ºÍ´¦ÀíÉÌÒµÐÅÏ¢£¬Í¨¹ýERP£¨ÆóÒµ×ÊÔ´¼Æ»®ÏµÍ³£©×¼È·¼à¿ØÐÅÏ¢Á÷£¬´Ó¶ø¶ÔÆóÒµ¾ÓªµÄ¸÷¸ö·½Ãæ½øÐйÜÀí¡£ÕâЩϵͳ³ýÁ˱¾ÉíµÄÓ¦ÓÃÍ⣬»¹»ýÀÛÁË´óÁ¿µÄÊý¾Ý£¬ÈçÀ´×ÔÒµÎñϵͳµÄ¶© ......