mysql´´½¨±íµÄ×ֶΠĬÈÏΪ 0Öµ
ÓÃmysql5.1
ͼÐνçÃæ¹¤¾ßÊÇ SQLyogÆóÒµ°æ¡£
´´½¨Ò»¸ö±íʱ ÓÐÒ»¸ö×Ö¶ÎΪscore£¨int£© ÎÒÉèÖÃÁËĬÈÏֵΪ 0 £¬µ«ÎªÊ²Ã´ ÏÔʾµÄ»¹ÊÇnull¡£¡£
mysql Èç¹û²»ÉèÖõϰ ĬÈϾÍΪnull ÕâÑù ¶ÁÈ¡ÆðÀ´ ºÜÀË·ÑЧÂÊ¡£¡£
¾ÍÏñoracle Ò»Ñù ÉèÖÃÁË Ä¬ÈÏÖµ ±ãÏÔʾĬÈÏÖµ ¡£¡£¡£
Çó½Ì¡£¡£¡£¡£¡£¡£¡£¡£
show create table ¿´Ò»ÏÂ
Á½ÖÖ¿ÉÄÜ¡£
1¡£ ÄãµÄ×Ö¶ÎÉÏÉèÖÃĬÈÏֵûÓгɹ¦¡£
2¡£ ÄãµÄ²åÈëÓï¾äÓÐÎÊÌ⣬ֱ½Ó²åÈëµÄ¾ÍÊÇNULL
ÎÊÌâ ½â¾öÁË¡£ÊÇSQLyogµÄÑÓ³ÙÎÊÌâ¡£¶àˢм¸´Î¾ÍºÃÁË¡£¡£ÓÃsqlÓï¾ä´´½¨ºÍ ÔÚguiÀï±ß É趨defaultֵЧ¹û¶¼ÊÇÒ»ÑùµÄ¡£¶àл¶þλ°ïæ¡£
Ïà¹ØÎÊ´ð£º
±àÒëÆ÷£ºC-Free4
mysql µ¥¶À°²×°µÄ£¬ÏÖÔÚΪapache+php+mysql¿ÉÒÔʹÓá£
×î½üÔÚÁ·Ï°c£¬c++£»ÏëÓÃc£¬c++Á¬½ÓÏÂÎÒµÄmysql£¬ºÃ¶àµØ·½¶à˵mysql.hÕÒ²»µ½¡£¶øÇÒÎÒmysqlûÓÐËùνµÄincludeÎļþ¼Ð°¡¡£
Íü¸ßÊÖÖ¸µãÒ»¶ ......
ÎÒ¶ÔSQL SERVERºÍACCESS±È½ÏÊ죬ËùÒÔÊý¾Ý¿âµÄͨÓûù´¡¶«Î÷¿ÉÒÔ˵¶¼ÕÆÎյIJ¶àÁË£¬ÎÒÏÖÔÚÏëÒªµÄ¾ÍÊÇÒÔÉÏÁ½Êý¾Ý¿âµÄ¶ÀÌØÖ®´¦µÄ½éÉܺÍÓ¦ÓýéÉÜ¡£
ÁíÍâÊé×îºÃ¶ÔÓ¦×îа汾 oracleÊÇ11g°É 10µÄÒ²ÐУ»mysqlÊÇ5.1°É
л ......
hql = "select left('adfsadfasgsadgagsda',2)";
¾ÍÓÃÕâ¾äÓï¾ä ÔÚÊý¾Ý¿âÖÐÖ´ÐÐ
µ«ÊÇÔÚjava´úÂëÖÐ ÓÃHibernate Ö´ÐÐ ¾Í²»ÄÜÖ´ÐÐ £¿
ÕâÊÇʲôÎÊÌ⣡£¡£¡
ÎÒÒѾ֪µÀÁË£¡
&n ......
String sqlCount="select count(*) from usertable where username='"+
userName+"'";Õâ¾ä»° ʲôÒâ˼°¡£¡
Õâ¾ä»°Êä³ö³öÀ´¾ÍÊÇ
select count(*) from usertable where username='ÄãµÄ±äÁ¿ ......
ÎÒÏÖÔÚÏëÓÃJSPʵÏÖQQÓÊÏäÀïµÄ¶¨Ê±·¢ËÍ£¬ÎÒÏëͨ¹ýÊý¾Ý¿â½øÐж¨Ê±²åÈëÊý¾Ý¡£
µ«²»ÖªµÀÈçºÎʵÏÖ£¬»òÕß´ó¼ÒÓиüºÃµÄ·½·¨£¬²»Ò»¶¨ËµÊÇÊý¾Ý¿â¡£
Çë´ó¼Ò¸øµãÒâ¼û£¬°ÝлÀ²¡£
quataz¶¨Ê±Æ÷×é¼þÊǸöºÜºÃµÄ½â¾ö·½°¸¡£
È ......