Ò»¸ö¼òµ¥µÄMysqlµÄÁªºÏ²éѯÁÐ×Ó
Ò»¸ömysqlµÄÁªºÏ²éѯÁÐ×Ó£¬ºÜ»ù±¾µÄ£¬²»¹ýºÜʵÓá£
ÏÈ¿´Êý¾Ý±í¡£Êý¾Ý±íclass£º
-------------------------------
id cname
-------------------------------
1 ÄÐ×°
2 ŮƤ¿ã
3 Å®²ÊÃÞ
-------------------------------
class±í´æ·ÅµÄÊDzúÆ·µÄ´óÀàÃû³ÆºÍÆäÐòºÅ
Êý¾Ý±íproduct£º
-------------------------------
pid ptype pparent
-------------------------------
1 A01 1
2 A21 1
3 B10 2
4 C11 3
5 C01 2
-------------------------------
product±í´æ·ÅµÄÊDzúÆ·Ãû³Æ£¬ºÍÆäËùÊô´óÀàµÄid£¨pparent£©
ÏÖÔÚÒªÇóÏÔʾËùÓвúÆ·ÐòºÅ¡¢Ãû³Æ¡¢ËùÊôÀà±ð£¬ÈçÏÂÐÎʽ£º
-------------------------------
ÐòºÅ Ãû³Æ Àà±ð
-------------------------------
1 A01 ÄÐ×°
2 A21 ÄÐ×°
3 B10 ŮƤ¿ã
4 C11 Å®²ÊÃÞ
5 C01 ŮƤ¿ã
-------------------------------
ÕâÀïÒª²éѯproduct±í£¬¸ù¾Ýpparent×Ö¶ÎÔÙ¶Á³ö¶ÔÓ¦µÄclass±íÖÐpname×ֶΡ£×ͳµÄ£¬¿ÉÒÔÓÃÁ½¸öselectÓï¾äʵÏÖ£¬µ«ÊÇmysqlÖÐÓÐÁªºÏ²éѯÓï¾ä¿ÉÒÔ¼òµ¥µÄʵÏÖ£º
select product.*, class.* from product inner join class on product.pparent=class.id where product.pid is not null
ÔÚphpÖУ¬Í¨¹ýÕâÑù²éѯ³öÀ´µÄ¼Ç¼¶¼·ÅÔÚÊý×éÀïÃæ£¬±ÈÈ磺
$myrow=mysql_fetch_array(mysql_query($sql));
ÄÇô$myrowÊý×éÖУ¬Ç°Ãæ´æ·ÅµÄÊÇproductÖеÄ×ֶΣ¬ºóÃæ´æ·ÅµÄÊÇclassµÄ×ֶΡ£
Ïà¹ØÎĵµ£º
ͨ¹ýMySQLÄÚÖÃÈ«ÎļìË÷ʵÏÖÖÐÎĵÄÏà¹Ø¼ìË÷
¹Ø¼ü×Ö£ºMySQL È«ÎļìË÷ È«ÎÄË÷Òý ÖÐÎÄ·Ö´Ê ¶þÔª·Ö´Ê ÇøÎ»Âë ÏàËÆ¶È
×¢£º±¾ÎÄʹÓõÄMySQL°æ±¾Îª£ºMySQL 4.0.x
ÔÚMySQL4ÖУ¬ÊÇÒѾ¿ªÊ¼Ö§³ÖÈ«ÎļìË÷£¨Ë÷Òý£©µÄÁË¡£µ«ÊÇÖ»ÊǶÔÓ¢ÎÄÖ§³ÖÈ«ÎļìË÷¡£
ÓÉÓÚÓ¢ÎÄÔÚÊéдÉϵÄÌØÊâÐÔ£¬Ê¹µÃ·Ö´ÊËã·¨Ïà¶ÔÖÐÎÄÀ´Ëµ£¬¼òµ¥µÃ¶à¡£Ò»°ãÀ´Ëµ£¬ÎÒÃÇ ......
֮ǰ£¬ÓÉÓÚ¿Í»§ÒªÇóÔÚcentOSϰ²×°ÏµÍ³Ó¦Óã¬Òò´ËÓлú»á½Ó´¥ÁËÒ»ÏÂCentOS£¬Ë³±ãÒ²Á˽âÁËÏÂCentOSµÄ³£¹æ²Ù×÷£¬»¹ÓÐÔÚCentOSϵÄMySQLÏà¹Ø²Ù×÷¡£
Ŀǰ¼¼Êõ¿ò¼ÜʹÓÃJSF£¨richfaces¡¢facelets£©+Spring+JPA£¨OpenJPA£©£¬²»Ê¹ÓÃÊý¾Ý¿âÒÀÀµµÄ´¥·¢Æ÷»ò´æ´¢¹ý³Ì£¬ËùÓÐÒµÎñÂß¼ÔÚweb·þÎñÆ÷ÉÏÖ´ÐУ¬Òò´ËÊý¾Ý¿â»ù±¾²»Óÿ¼ÂÇÒÆ ......
Ë÷ÒýµÄ´ú¼Û
¡¡¡¡Ò»°ãÀ´Ëµ£¬Èç¹ûMySQLÄܹ»ÕÒµ½·½·¨£¬ÀûÓÃË÷ÒýÀ´¸ü¿ìµØ´¦Àí²éѯ£¬Ëü¾Í»áÕâÑù×ö¡£Õâ
Òâζ×Å£¬¶ÔÓÚ´ó¶àÊýÇé¿ö£¬Èç¹ûÄãûÓÐ¶Ô±í½øÐÐË÷Òý£¬¾Í»áʹÐÔÄÜÊܵ½Ë𺦡£Õâ¾ÍÊÇÎÒËùÃè»æµÄË÷ÒýÓŵãµÄÃÀ¾°¡£µ«ÊÇËüÓÐȱµãÂð£¿Óеģ¬ËüÔÚʱ¼äºÍ¿Õ¼äÉ϶¼Óпª
Ïú¡£ÔÚʵ¼ùÖУ¬Ë÷ÒýµÄÓŵãµÄ¼ÛÖµÒ»°ã»á³¬¹ýÕâЩȱµã£¬µ«ÊÇÄ ......
user±í:
id | name
———
1 | libk
2 | zyfon
3 | daodao
user_action±í:
user_id | action
—————
1 | jump
1 | kick
1 | jump
2 | run
4 | swim
sql:
select id, name, action from user as u
left join user_action a on u.id = a.user_id
result:
id | ......
ÓкܶàÓ¦ÓÃÏîÄ¿, ¸ÕÆð²½µÄʱºòÓÃMYSQLÊý¾Ý¿â»ù±¾ÉÏÄÜʵÏÖ¸÷ÖÖ¹¦ÄÜÐèÇó£¬Ëæ×ÅÓ¦ÓÃÓû§µÄÔö¶à£¬Êý¾ÝÁ¿µÄÔö¼Ó£¬MYSQL½¥½¥µØ³öÏÖ²»¿°ÖظºµÄÇé¿ö£ºÁ¬½ÓºÜÂýÉõÖÁå´»ú£¬ÓÚÊǾÍÓаÑÊý¾Ý´ÓMYSQLǨµ½ORACLEµÄÐèÇó£¬Ó¦ÓóÌÐòÒ²ÒªÏàÓ¦×öһЩÐ޸ġ£±¾ÈË×ܽá³öÒÔϼ¸µã×¢ÒâÊÂÏϣÍû¶Ô´ó¼ÒÓÐËù°ïÖú¡£
1£® ×Ô¶¯Ôö³¤µÄÊý¾ ......