SQLÁª±í¸üУ¬Áª±í²éѯ
ûÓÐÒýÓùØÏµµÄ±í
£±.¡¡Áª±í¸üÐÂ
update a set a.education = '±¾¿Æ' from NT_UserInfo a ,NT_User b where a.UserID=b.UserID and b.email = 'carlfan2008@163.com'
£².¡¡Áª±í²éѯ
select a.*,b.* from nt_user as a, nt_userinfo as b where a.userid = b.userid and Email = 'carlfan2008@163.com'
Ïà¹ØÎĵµ£º
SQLÖÐonÌõ¼þÓëwhereÌõ¼þµÄÇø±ð
Êý¾Ý¿âÔÚͨ¹ýÁ¬½ÓÁ½ÕÅ»ò¶àÕűíÀ´·µ»Ø¼Ç¼ʱ£¬¶¼»áÉú³ÉÒ»ÕÅÖмäµÄÁÙʱ±í£¬È»ºóÔÙ½«ÕâÕÅÁÙʱ±í·µ»Ø¸øÓû§¡£
ÔÚʹÓÃleft jionʱ£¬onºÍwhereÌõ¼þµÄÇø±ðÈçÏ£º
1¡¢ onÌõ¼þÊÇÔÚÉú³ÉÁÙʱ±íʱʹÓõÄÌõ¼ ......
Ëæ×ÅB/SģʽӦÓÿª·¢µÄ·¢Õ¹£¬Ê¹ÓÃÕâÖÖģʽ±àдӦÓóÌÐòµÄ³ÌÐòÔ±Ò²Ô½À´Ô½¶à¡£µ«ÊÇÓÉÓÚÕâ¸öÐÐÒµµÄÈëÃÅÃż÷²»¸ß£¬³ÌÐòÔ±µÄˮƽ¼°¾ÑéÒ²²Î²î²»Æë£¬Ï൱´óÒ»²¿·Ö³ÌÐòÔ±ÔÚ±àд´úÂëµÄʱºò£¬Ã»ÓжÔÓû§ÊäÈëÊý¾ÝµÄºÏ·¨ÐÔ½øÐÐÅжϣ¬Ê¹Ó¦ÓóÌÐò´æÔÚ°²È«Òþ»¼¡£Óû§¿ÉÒÔÌá½»Ò»¶ÎÊý¾Ý¿â²éѯ´úÂ룬¸ù¾Ý³ÌÐò·µ»ØµÄ½á¹û£¬»ñµÃijЩËûÏëµÃÖªµÄÊ ......
SQL UNION ²Ù×÷·û
UNION ²Ù×÷·ûÓÃÓںϲ¢Á½¸ö»ò¶à¸ö SELECT Óï¾äµÄ½á¹û¼¯¡£
Çë×¢Ò⣬UNION ÄÚ²¿µÄ SELECT Óï¾ä±ØÐëÓµÓÐÏàͬÊýÁ¿µÄÁС£ÁÐÒ²±ØÐëÓµÓÐÏàËÆµÄÊý¾ÝÀàÐÍ¡£Í¬Ê±£¬Ã¿Ìõ SELECT Óï¾äÖеÄÁеÄ˳Ðò±ØÐëÏàͬ¡£
SQL UNION Óï·¨
SELECT column_name(s) from table_name1
UNION
SELECT column_name(s) from tabl ......
--Óï ¾ä ¹¦ ÄÜ
1¡¢Êý¾Ý²Ù×÷
Select --´ÓÊý¾Ý¿â±íÖмìË÷Êý¾ÝÐкÍÁÐ
Insert & ......
http://cheneyph.javaeye.com/blog/453492
ÓÃoracle sql¶ÔÊý×Ö½øÐвÙ×÷: È¡ÉÏÈ¡Õû¡¢ÏòÏÂÈ¡Õû¡¢±£ÁôNλСÊý¡¢ËÄÉáÎåÈë¡¢Êý×Ö¸ñʽ»¯
È¡Õû£¨ÏòÏÂÈ¡Õû£©£º
select floor(5.534) from dual;
select trunc(5.534) from dual;
ÉÏÃæÁ½ÖÖÓ÷¨¶¼¿ÉÒÔ¶ÔÊý×Ö5.534ÏòÏÂÈ¡Õû£¬½á¹ûΪ5.
Èç¹ûÒªÏòÉÏÈ¡Õû £¬µÃµ½½á¹ûÎ ......