mysql ²éѯÓï¾ä
select id,dtime,zt,optype( Èç¹ûoptype=0½«±¾ÌõÊý¾Ý²åÈëµ½table1±íÖУ¬Èç¹ûoptype=1ÒÔdtimeºÍztΪÌõ¼þÖ´ÐÐÒ»Ìõ²éѯÓï¾ä ) from table
ʵÏÖÕâ¸öÒªÇóµÄÓï·¨Ôõôд
Ò»ÌõSQLÓï¾ä¹À¼Æ¸ã²»¶¨¡£µÈ¥Ϻ÷½·¨£¡
Èç¹ûoptype=1ÒÔdtimeºÍztΪÌõ¼þÖ´ÐÐÒ»Ìõ²éѯÓï¾ä
ûÓÐÀí½âÊÇʲôÒâ˼£¬¾ÙÀý˵Ã÷ÄãµÄÒªÇó
¾ÍÊÇÖ´ÐвéѯÁíÒ»¸ö±íµÄselectÓï¾ä Á½¸ö±íµÄÁÐÒ»Ñù
¾ÙÀý˵Ã÷ÄãµÄÒªÇó
»¹ÊÇ×òÌìµÄÎÊÌâ°¡¡£
ÄãÕâÑùÎÊÄÜÕýÈ·Àí½âµÄÈ˺ÜÉÙ°¡£¨ÊÂʵҲ֤Ã÷£©
½¨ÒéÄãÓÃÀý×Ó°É¡£
SQL code:
delimiter //
drop procedure if exists getData;//
create procedure getData()
begin
declare num,i,nid int default 1;
declare strtype varchar(50);
select count(*) into num from tjmain;
while i < num do
select id into nid from tjmain limit i,1 ;
select nid;
set i = i + 1 ;
end while;
end
Õâ¸ö´æ´¢¹ý³ÌµÄ²éѯÓï¾älimitºó±ß²»ÄÜÓñäÁ¿´úÌæÃ´£¿
²»ÄÜ£¬ÓÃCONCATÁ¬½Ó×Ö·û´®£¬ÓÃPREPARE¡¡EXECUTE¶¯Ì¬Ö´ÐÐSQL¡¡
¸ø¸öÀý×Ó¿´¿´¡£¡£¡£
ÄãµÄÒâ˼ÊǰѲéѯÓï¾äÓÃ×Ö·ûÆ´ÆðÀ´ÔÚÖ´ÐУ¿
Èç¹ûÔÚ´æ´¢¹ý³ÌÖУ¬ÎÞ·¨ÊµÏÖ£¬¼´Ê¹Óà prepare stmt Ò²²»ÐС£
´ÖÂÔ¿´ÁËһϣ¬Æäʵ¿ÉÒÔÖ±½ÓÓÃÓαêÀ´ÊµÏÖ¡£
ÓαêÈçºÎʵÏÖ¡£¡£¡£
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»¶ ......
´ÓÆô¶¯µ½ÄÜÕý³£ÔËÐÐ,´ó¸ÅÒª15µ½20·ÖÖÓ×óÓÒ
ÏÖÏóÊÇ,Æô¶¯ÒÔºómysql½ø³ÌÔÚÈÎÎñ¹ÜÀíÆ÷ÀïÒѾ¿ÉÒÔ¿´µ½ÁË,µ«ÊÇnetstat -anoûÓп´µ½Óнø³ÌÔÚ¼àÌý3306¶Ë¿Ú,ÉÏÃæÊý¾Ý¿â¶¼²»ÄÜ·ÃÎÊ
Ö±µ½15-20·ÖÖÓºó,ÄÜ¿´µ½mysqlÔÚ¼à ......
ÏÖÓÐÒ»¸ö±íÓÐ185ÍòÌõ¼Ç¼
ËÑË÷ʱ£¬×î¸ß·åÖµ¿É´ï1.2G×óÓÒ
ʹÓÃmy-xxx.ini±È½ÏºÃ£¿£¡
ÈçºÎ½«ÕâЩÅäÖñä³ÉĬÈÏÅäÖã¿£¡
°ÑÔÀ´µÄ my.ini ¸ÄÃû±¸·Ý£¬È»ºóÔÙ°ÑÕâ¸ö my-huge.ini ¸Ä³É my.ini
» ......
MySqlÖвåÈ뵱ǰʱ¼äµÄ¸ÃÔõôд°¡£¿
now()
SQL code:
sqlÀïÊÇ£º
getdate()
ÒýÓÃ
now()
ѧϰ
SQL code:
select now();
SQL code:
TODAY()
?
SQL code:
select now();
/* ......
mysqlÃüÁîÐпͻ§¶ËÏÔʾÂÒÂë
mysql> select * from userinfo;
+--------+----------+----------+------+-----------+-----------+
| autoid | username | password | sex | realname | q ......