sqlÓï¾äµÄʹÓÃ
ÒÔÏÂÊÇÎÒÔÚѧϰÖеĵãµÎ¼Ç¼£¬Èç¹ûÓдíÎóµÄµØ·½»òÕßȱÉÙ²¿·Ö£¬Çë¸÷λ´óÏÀ²»ÁßÖ¸½Ì¡£Ð¡µÜÔÚ´Ëл¹ýÁË
1.select count£¨*£© ºÍselect count£¨id£© Ö®¼äµÄÇø±ð¡£
select count(*) ͳ¼ÆËùÓмǼ¸öÊý£¬°üÀ¨¿Õ¼Ç¼¡£
Select count(Id) ͳ¼ÆËùÓмǼ¸öÊý£¬²»°üÀ¨null¼Ç¼¡£
2.delete & truncate µÄÇø±ð
truncate
ʹÓ÷½·¨£º
¡¡ ¡¡truncate table table_name£»
¡¡ ¡¡²Ù×÷ÌØÐÔ£º
¡¡ ¡¡truncate ֻɾ³ý±íÖеÄËùÓÐÊý¾Ý£¬²»É¾³ý±íµÄ½á¹¹£»
¡¡ ¡¡truncate ÊÇddl²Ù×÷Á¢¼´ÉúЧ£¬ÔÊý¾Ý²»·Åµ½rollback segmentÖУ¬²»Äܻعö.£¬²Ù×÷²»´¥·¢trigger.£»
delete ¶ÔÿÌõ¼Ç¼µÄɾ³ý¾ùÐèÒª¼Ç¼ÈÕÖ¾
Ïà¹ØÎĵµ£º
http://www.umgr.com/blog/PostView.aspx?bpId=36294
1. Ö´ÐÐsqlÓï¾ä
int sqlite3_exec(sqlite3*£¬ const char *sql£¬ sqlite3_callbacksql Óï·¨
£¬ void *£¬ char **errmsg );
Õâ¾ÍÊÇÖ´ÐÐÒ»Ìõ sql Óï¾äµÄº¯Êý¡£
µÚ1¸ö²ÎÊý²»ÔÙ˵ÁË£¬ÊÇÇ°Ãæopenº¯ÊýµÃµ½µÄÖ¸Õ롣˵ÁËÊǹؼüÊý¾Ý½á¹¹¡£
µÚ2¸ö²ÎÊýconst char ......
SQL Server .NET Framework Êý¾ÝÌṩ³ÌÐò (SqlClient) Ìṩ¾ÛºÏº¯Êý¡£¾ÛºÏº¯Êý¶ÔÒ»×éÊäÈëÖµÖ´ÐмÆËã²¢·µ»ØÒ»¸öÖµ¡£ÕâЩº¯ÊýλÓÚ SqlServer ÃüÃû¿Õ¼äÖУ¬¸ÃÃüÃû¿Õ¼äÔÚÄúʹÓà SqlClient ʱ¿ÉÓá£Ìṩ³ÌÐòµÄÃüÃû¿Õ¼äÊôÐÔʹʵÌå¿ò¼Ü¿ÉÒÔÈ·¶¨´ËÌṩ³ÌÐò¶ÔÌØ¶¨¹¹Ô죨ÈçÀàÐͺͺ¯Êý£©Ê¹ÓÃÄĸöǰ׺¡£
ϱíÏÔʾ SqlClient ¾ÛºÏº¯Êý¡£ ......
select getdate()
ÊÇÏÔʾµ±Ç°ÏµÍ³Ê±¼ä£¬Êä³öµÄÈÕÆÚ¸ñʽÓë±¾»úÈÕÆÚ¸ñʽÓйأ¬¼ÙÈëÄãÏëÔÚʲôÇé¿ö϶¼ÏÔʾ³É2006-12-15 10:37:00ÕâÖÖÐÎʽÔòÐèҪת»»Ò»ÏÂ
select convert(varchar(30),getdate(),20)
ÏÔʾÊÇÐÇÆÚ¼¸µÄÓï¾äÊÇ
select datename(weekday,getdate())
ÈÕÆÚ¼ÓÐÇÆÚµÄ»°Ö±½Ó¼ÓÔÚÒ»¿é¾Í¿ÉÒÔÁË
select convert(varcha ......
SQL Server 2005 Áª»ú´ÔÊ飨2008 Äê 11 Ô£©
SQL Server 2005 µÄĬÈÏʵÀýºÍÃüÃûʵÀýµÄÎļþλÖÃ
¸üÐÂÈÕÆÚ£º 2005 Äê 12 Ô 5 ÈÕ
Microsoft SQL Server 2005 µÄ°²×°°üº¬Ò»¸ö»ò¶à¸öµ¥¶ÀµÄʵÀý¡£ÎÞÂÛÊÇĬÈϵϹÊÇÃüÃûµÄʵÀý£¬¶¼ÓÐ×Ô¼ºµÄÒ»Ì׳ÌÐòÎļþºÍÊý¾ÝÎļþ£¬ÒÔ¼°Ò»Ì×ÔÚ¼ÆËã»úÉϵÄËùÓÐʵÀýÖ®¼ä¹²ÏíµÄ¹«¹²Îļþ¡£
¶ÔÓÚ°üº ......
ÎÒÃÇÒª×öµ½²»µ«»áдSQL,»¹Òª×öµ½Ð´³öÐÔÄÜÓÅÁ¼µÄSQL,ÒÔÏÂΪ±ÊÕßѧϰ¡¢ÕªÂ¼¡¢²¢»ã×ܲ¿·Ö×ÊÁÏÓë´ó¼Ò·ÖÏí£¡
£¨1£© Ñ¡Ôñ×îÓÐЧÂʵıíÃû˳Ðò(Ö»ÔÚ»ùÓÚ¹æÔòµÄÓÅ»¯Æ÷ÖÐÓÐЧ)£º
ORACLEµÄ½âÎöÆ÷°´ÕÕ´ÓÓÒµ½×óµÄ˳Ðò´¦Àífrom×Ó¾äÖеıíÃû£¬from×Ó¾äÖÐдÔÚ×îºóµÄ±í(»ù´¡±í driving table)½«±»×îÏÈ´¦Àí£ ......