Ò׽ؽØÍ¼Èí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

sqlÎÊÌâ

ÎÒµÄsqlÓï¾äÊÇÕâÑùµÄ£¬¡°select count(id) , a, b from abc¡±£¬ÎÒÏëÒªµÄ½á¹ûÊÇ£¬¼ÈÓÐabc±íÖÐ×ܵÄÐÐÊý£¨Ò²¾ÍÊÇcount£©,»¹ÏëÒªabc±íÖеÄËùÓеÄa£¬b×ֶεĽá¹û¼¯£¬ÇëÎÊsql¸ßÊÖ£¬Õâ¸ö¸ÃÔõôʵÏÖ£¿ÎÒµÄÕâ¸ösqlÓï¾äÊǿ϶¨²»Ðеģ¬ËüÖ»·µ»ØÀ´Ò»ÐмǼ¡£Ð»Ð»¸÷λ
ÄãÕâ¸öµÃGROUP BYÁË¡£

û¿´¶®ÄãµÄ¡°»¹ÏëÒªabc±íÖеÄËùÓеÄa£¬b×ֶεĽá¹û¼¯¡± ÊÇʲôÒâ˼¡£

½¨ÒéÄãÁгöÄãµÄ±í½á¹¹£¬²¢Ìṩ²âÊÔÊý¾ÝÒÔ¼°»ùÓÚÕâЩ²âÊÔÊý¾ÝµÄËù¶ÔÓ¦ÕýÈ·½á¹û¡£

SQL code:

select a,b,(select count(id) from abc) as c
from abc;



SQL code:
select t1.a, t1.b, t2.total_count from abc t1 cross join (select count(*) as total_count from abc) t2


ÔΣ¬ÉÏÃæÃ÷Ã÷×îºóÊÇt2µÄ
Õâ¸öÓÖÊÇcsdnµÄÒ»¸öbug?

group by
join

id¶ÔÓ¦ ÒªÓÃÁ½¸ö±íÁ´½Ó»òÕßjoin


Ïà¹ØÎÊ´ð£º

Á½¸öµ¼¹¹sql serverÊý¾Ý¿â,Êý¾Ýµ¼Èëµ¼³öÎÊÌâ

ÏÖÔÚÓÐÁ½¸öÒì¹¹µÄsql serverÊý¾Ý¿â,ÎÒÏ뽫µÚÒ»¸ö±íÖеÄÊý¾Ýµ¼Èëµ½µÚ¶þ¸ö±íÖÐ,×Ô¼ºÖ¸¶¨µ¼ÈëÊý¾ÝµÄ×Ö¶Î,ÈçºÎµ¼ÈëÊý¾ÝÄØ,´ó¼ÒÌÖÂÛÒ»ÏÂ?
dts¹¤¾ß

µ¼Èëµ¼³ö¹¤¾ß.

DD

¹þ¹þ£¬¹À¼ÆÕâλÊǵØQIOU¶¼Êܲ»Á˵Ä

Ö±½ÓÐ ......

sql ÎÊÌâ

PBÖпª·¢µÄ¡£

DateTime startTime=DateTime(em_1.Text)
DateTime endTime=DateTime(em_2.Text)

string sql
sql = dw_1.GetSQLSelect()+"Where (StartTime> '"+startTime+&q ......

sqlÓï¾äÖÐÄܲ»ÄÜÕâÑùÅÅÐò£¿

Êý¾Ý±í¡¾biao¡¿£¬
×ֶΣºid¡¢myname¡¢mytxt
mytxtÄÚÈݸñʽÐÎÈ磺n|abcd¡££¨ÀýÈ磺1|ÁõµÂ»ª£¬2|Èδﻪ£¬3|αÌϼ£¬4|Âõ¿Ë@½Ü¿ËÑ·£©

ÎÒÏÖÔÚÏ£Íû¶Á¼Ç¼³öÀ´ºó£¬°´ÕÕ[mytxt]×Ö¶ÎÀïµÄÊúÏߣ¨|£©Ç°ÃæµÄÄǸöÊý× ......

ÇóÒ»¸ösql Óï¾ä

  table1
  Ãû³Æ      Èë¿âÊý
  CT»ú        3   
  CT»ú        5
  X¹â»ú      4 ......

sql¿ÉÒÔÓÐÁ½¸öÒÔÉϵĴ¥·¢Æ÷Â𣿣¿

sql¿ÉÒÔÓÐÁ½¸öÒÔÉϵĴ¥·¢Æ÷Â𣿣¿ÎÒÖ¸µÄÊÇfor´¥·¢Æ÷£¬ÄÇÆäËûµÄÄØ£¿£¿
ʲôÒâ˼£¿

¿ÉÒÔµÄ

10¸ö¶¼Ã»ÎÊÌâ

¿ÉÊÇÎÒдÁËÁ½¸öfor insert ´¥·¢Æ÷£¬Ôì³É½ø³Ì×èÈûÁËÄØ£¿Ôõô°ìÄØ£¿Çë¸ßÈËÖ¸µã
......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ