¼¸µÀ¾µäµÄSQL±ÊÊÔÌâÄ¿
¼¸µÀ¾µäµÄSQL±ÊÊÔÌâÄ¿£¨Óд𰸣©
£¨1£©±íÃû£º¹ºÎïÐÅÏ¢
¹ºÎïÈË ÉÌÆ·Ãû³Æ ÊýÁ¿
A ¼× 2
B ÒÒ 4
C ±û 1
A ¶¡ 2
B ±û 5
……
£¨ÆäËûÓû§ÊµÑéµÄ¼Ç¼´ó¼Ò¿É×ÔÐвåÈ룩
¸ø³öËùÓйºÈëÉÌÆ·ÎªÁ½ÖÖ»òÁ½ÖÖÒÔÉϵĹºÎïÈ˼Ǽ
´ð£ºselect * from ¹ºÎïÐÅÏ¢ where ¹ºÎïÈË in (select ¹ºÎïÈË from ¹ºÎïÐÅÏ¢ group by ¹ºÎïÈË having count(*) >= 2);
£¨2£©±íÃû£º³É¼¨±í
ÐÕÃû ¿Î³Ì ·ÖÊý
ÕÅÈý ÓïÎÄ 81
ÕÅÈý Êýѧ 75
ÀîËÄ ÓïÎÄ 56
ÀîËÄ Êýѧ 90
ÍõÎå ÓïÎÄ 81
ÍõÎå Êýѧ 100
ÍõÎå Ó¢Óï 49
……
£¨ÆäËûÓû§ÊµÑéµÄ¼Ç¼´ó¼Ò¿É×ÔÐвåÈ룩
¸ø³ö³É¼¨È«²¿ºÏ¸ñµÄѧÉúÐÅÏ¢£¨°üº¬ÐÕÃû¡¢¿Î³Ì¡¢·ÖÊý£©£¬×¢£º·ÖÊýÔÚ60ÒÔÉÏÆÀΪºÏ¸ñ
´ð£ºselect * from ³É¼¨±í where ÐÕÃû not in (select distinct ÐÕÃû from ³É¼¨±í where ·ÖÊý < 60)
»òÕߣº
select * from ³É¼¨±í where ÐÕÃû in (select ÐÕÃû from ³É¼¨±í group by ÐÕÃû having min(·ÖÊý) >=60)
£¨3£©±íÃû£ºÉÌÆ·±í
Ãû³Æ ²úµØ ½ø¼Û
Æ»¹û ÑĮ̀ 2.5
Æ»¹û ÔÆÄÏ 1.9
Æ»¹û ËÄ´¨
Ïà¹ØÎĵµ£º
Ò»¡¢³õʼ°²×°ÇëÏȰ²×°sqlserver 2000 ÔÙ°²×°sqlserver 2005
¶þ¡¢Èç¹ûÖÐ;sqlserver2000Óöµ½ÎÊÌâÐèÒªÖØ×°£¬Çë°´ÒÔϲ½Öè
1.ÔÚ¿ØÖÆÃæ°å->Ìí¼Óɾ³ý³ÌÐòÖÐɾ³ýsqlserver2000
2.ÔÚ¹ÜÀí¹¤¾ß->·þÎñÖÐÍ£Ö¹sqlserverµÄËùÓзþÎñ
3.ÊÖ¶¯É¾³ýC:\Program Files\Microsoft SQL ServerĿ¼ÏµÄ80Ŀ¼ºÍMSSQLĿ¼£¨±ØÐëÒªÓеڶþ² ......
ºÜ¶à¼¼Êõ°®ºÃÕߵĵçÄÔÉÏ×ÜÊǰ²×°Á˺ܶàÈí¼þ£¬°üÀ¨Ó¦ÓÃÈí¼þ¡¢¿ª·¢¹¤¾ßÈí¼þ¼°Êý¾Ý¿âÈí¼þ£¬µ«ÊÇËæ×Åʱ¼äµÄÁ÷ÊÅ£¬ÂýÂýµØµçÄÔÉÏ×°µÄÈí¼þÒѾ³¬³öÁ˵çÄÔ±¾ÉíËùÄÜ
³ÐÔØµÄÁ¿ÁË£¬Òò¶ø³öÏÖÁ˵çÄÔÔËÐÐËÙ¶ÈÂýµÈÎÊÌ⡣ͬʱ£¬Ò²ÓÐһЩµ¥Î»»ò¸öÈ˵ĵçÄÔÓÉÓÚ³ö³§Äê´úÓÐЩ¾ÃÔ¶£¬¼´Ê¹Ö»°²×°Ò»ÖÖ»ò¼«ÉÙÊýÈí¼þʱҲ»áÏÔʾ³öÔËÐÐËÙ¶ÈÂý
µÄÏÖÏó¡£ ......
ÍâÁª½Ó:ÍâÁª½Ó¿ÉÒÔÊÇ×óÏòÍâÁª½Ó¡¢ÓÒÏòÍâÁª½Ó»òÍêÕûÍⲿÁª½Ó¡£
ÔÚ from ×Ó¾äÖÐÖ¸¶¨ÍâÁª½Óʱ£¬¿ÉÒÔÓÉÏÂÁм¸×鹨¼ü×ÖÖеÄÒ»×éÖ¸¶¨£º
LEFT JOIN »ò LEFT OUTER JOIN;
×óÏòÍâÁª½ÓµÄ½á¹û¼¯°üÀ ......
ÏÂÁÐÓï¾ä²¿·ÖÊÇMssqlÓï¾ä£¬²»¿ÉÒÔÔÚaccessÖÐʹÓá£
SQL·ÖÀࣺ
DDL—Êý¾Ý¶¨ÒåÓïÑÔ(CREATE£¬ALTER£¬DROP£¬DECLARE)
DML—Êý¾Ý²Ù×ÝÓïÑÔ(SELECT£¬DELETE£¬UPDATE£¬INSERT)
DCL—Êý¾Ý¿ØÖÆÓïÑÔ(GRANT£¬REVOKE£¬COMMIT£¬ROLLBACK)
Ê×ÏÈ,¼òÒª½éÉÜ»ù´¡Óï¾ä£º
1¡¢ËµÃ÷£º´´½¨Êý¾Ý¿â
CREATE DATABASE data ......
½ñÌìÁ·Ï°ÔÚJSPÒ³ÃæÖÐʵÏÖ·ÖҳЧ¹û£¬ÔÚ²éѯÓï¾ä·½ÃæÇ£³¶µ½ÁËtopµÄÓ÷¨¡£¼òÒª×öÒ»ÏÂ×ܽ᣺
ΪʵÏÖÀàËÆtopµÄ¹¦ÄÜ£¬ÎÒÃÇÔÚSQL ServerÖкÍMySQLÖÐʹÓõ½µÄSQLÓï¾äÊDz»Í¬µÄ¡£
1¡¢ÔÚSQL ServerÖУ¬ÎÒÃÇʹÓà select top N * ......