sqlʱ¼ä¶Îͳ¼Æ
ÓÐÁ½Õűí TB1 TB2
TB1½á¹¹
name(Ψһ) cdate
AA 2005/10/15
BB 2006/11/30
TB2½á¹¹
name(ÓÐÖØ¸´) date TTL
AA 2008/10/15 10
AA 2008/11/30 11
AA 2007/10/10 5
BB 2009/11/23 11
BB 2008/11/30 10
BB 2009/10/10 6
*******************************************************************
¼ÙÉ赱ǰʱ¼äΪ2009-11-24,Ôòn=11ÔÂ24 Y=2009
1.Èç¹ûn <cdate Ôòm1=(Y-1)/cdate(Ô
Ïà¹ØÎÊ´ð£º
select convert(varchar(50),cast(convert(numeric(18,2),1275674000000/100000000)as real))+'ÒÚ'
select cast(convert(numeric(18,2),1275674000000/100000000)as real)
ΪʲôÉÏÒ»¸öÓÃvarcharת»»ºó¾ÍÖ»±£ÁôÁËÒ ......
ΪÁËÂú×ãÊý¾Ý²éѯµÄËÙ¶ÈÎÊÌ⣬ÎÒ½«Ò»ÕÅÊý¾ÝÁ¿´óµÄѧÉú±í°´Äê¶È·Ö³É¶à¸ö±í
students_2008, students_2009È»ºóÎÒÓÖ×öÁËÒ»¸öÄ£°å±ístudents_template,Ä£°å±íÖеÄ×ֶκÍstudents_2008, students_2009Ò»Ñù£¬Ö»²»¹ýÊÇÒ»¸ö ......
ÎÒÒª×öÒ»¸ö¶¨µãʼþ£¬ÊÇÿÌìÍíÉÏ12µã¾Í°ÑÈý¸ö±íÀïµÄÐÅÏ¢·ÅÈëÒ»¸ö±íÀÎÒÏëÓô洢¹ý³ÌÀ´Ð´£¬ÔõÃ´Ð´ÄØ£¿£¬ÄÇλ¸ßÊÖ°ï°ïæ°É£¬·Ç³£¸Ðл£¡
Óû§ÃûÊÇΨһµÄ
±íA ×Ö¶Î
Óû§Ãû£ºName ,ÓÊÏ䣺Ema ......
³¡¾°ÈçÏ£º
¿Í»§°Ñ±¸·ÝºÃµÄÊý¾Ý¿â£¬·¢¸øÎÒ£¬ÎÒÔÚ±¾»ú»¹Ôºó£¬ÔËÐÐдºÃµÄ´æ´¢¹ý³Ì£¬±È½Ï¿ì£¬²¢ÇÒÔÚʵʩÄDZßÔËÐÐͬÑù±È½Ï¿ì¡£µ«Êǵ±ÊµÊ©ÔÚ¿Í»§ÄDZßÔËÐеÄʱºòËٶȾͷdz£µÄÂý£¬Ê±¼ä³¬³öÁ˳ÌÐòµÄʱ¼äÏÞÖÆ¡£Ô¶³ÌÔÚ¿Í»§ÄÇ ......
ÌâÄ¿£º°Ñ¡°SC¡±±íÖС°Ò¶Æ½¡±ÀÏʦ½ÌµÄ¿ÎµÄ³É¼¨¶¼¸ü¸ÄΪ´Ë¿Î³ÌµÄƽ¾ù³É¼¨£»
sqlÓï¾ä£º
update SC set score=(SELECT avg(SC_2.score)
from SC SC_2
WHERE S ......