select 1 from ... sqlÓï¾äÖеÄ1´ú±íʲôÒâ˼£¿
select 1 from ...£¬ sqlÓï¾äÖеÄ1´ú±íʲôÒâ˼£¿²é³öÀ´ÊǸöʲô½á¹û£¿
select 1 from table;Óëselect anycol(Ä¿µÄ±í¼¯ºÏÖеÄÈÎÒâÒ»ÐУ© from table;Óëselect * from table ´Ó×÷ÓÃÉÏÀ´ËµÊÇûÓвî±ðµÄ£¬¶¼ÊDz鿴ÊÇ·ñÓмǼ£¬Ò»°ãÊÇ×÷Ìõ¼þ²éѯÓõġ£select 1 from ÖеÄ1ÊÇÒ»³£Á¿£¨¿ÉÒÔΪÈÎÒâÊýÖµ£©£¬²éµ½µÄËùÓÐÐеÄÖµ¶¼ÊÇËü£¬µ«´ÓЧÂÊÉÏÀ´Ëµ£¬1>anycol>*£¬ÒòΪ²»Óòé×Öµä±í¡£
²âÊÔ³¡¾°£º£¨×ª×ÔÍøÂçÎÄÏ×£©
table±íÊÇÒ»¸öÊý¾Ý±í£¬¼ÙÉè±íµÄÐÐÊýΪ10ÐС£
1£ºselect 1 from table Ôö¼ÓÁÙʱÁУ¬Ã¿ÐеÄÁÐÖµÊÇдÔÚselectºóµÄÊý£¬ÕâÌõsqlÓï¾äÖÐÊÇ1
2£ºselect count(1) from table ¹Ücount(a)µÄaÖµÈçºÎ±ä»¯£¬µÃ³öµÄÖµ×ÜÊÇtable±íµÄÐÐÊý
3£ºselect sum(1) from table ¼ÆËãÁÙʱÁеĺÍ
ÔÚSQL SERVERÖÐÓà 1 ²âÊÔÁËһϣ¬·¢ÏÖ½á¹ûÈçÏ£º
1£º²âÊÔ½á¹û£¬µÃ³öÒ»¸öÐÐÊýºÍtable±íÐÐÊýÒ»ÑùµÄÁÙʱÁУ¨ÔÝÇÒÕâô½Ð£¬ÎÒÒ²²»ÖªµÀ¸Ã½Ðʲô£©£¬Ã¿ÐеÄÁÐÖµÊÇ1£»
2£ºµÃ³öÒ»¸öÊý£¬¸ÃÊýÊÇtable±íµÄÐÐÊý£»
3£ºµÃ³öÒ»¸öÊý£¬¸ÃÊýÊÇtable±íµÄÐÐÊý£»
È»ºóÎÒÓÖÓÓ2”²âÊÔ£¬½á¹ûÈçÏ£º
1£ºµÃ³öÒ»¸öÐÐÊýºÍtable±íÐÐÊýÒ»ÑùµÄÁÙʱÁУ¬Ã¿ÐеÄÁÐÖµÊÇ2£»
2£ºµÃ³öÒ»¸öÊý£¬¸ÃÊýÊÇtable±íµÄÐÐÊý£»
3£ºµÃ³öÒ»¸öÊý£¬¸ÃÊýÊÇtable±íµÄÐÐÊý×2µÄÊý
È»ºóÎÒÓÖÓøü´óµÄÊý²âÊÔ£º
1£ºµÃ³öÒ»¸öÐÐÊýºÍtable±íÐÐÊýÒ»ÑùµÄÁÙʱÁУ¬Ã¿ÐеÄÁÐÖµÊÇÎÒдÔÚselectºóµÄÊý£»
2£º»¹ÊǵóöÒ»¸öÊý£¬¸ÃÊýÊÇtable±íµÄÐÐÊý£»
3£ºµÃ³öÒ»¸öÊý£¬¸ÃÊýÊÇtable±íµÄÐÐÊý×дÔÚselectºóµÄÊý
×ÛÉÏËùÊö£ºµÚÒ»ÖÖµÄд·¨ÊÇÔö¼ÓÁÙʱÁУ¬Ã¿ÐеÄÁÐÖµÊÇдÔÚselectºóµÄÊý£»µÚ¶þÖÖÊDz»¹Ücount(a)µÄaÖµÈçºÎ±ä»¯£¬µÃ³öµÄÖµ×ÜÊÇtable±íµÄÐÐÊý£»µÚÈýÖÖÊǼÆËãÁÙʱÁеĺ͡£
Óï¾äif not exists(select 1 from deleted d join inserted i on d.ID=i.ID
and d.col1=1 and i.col1=2)
if not exists Èç¹û²»´æÔÚ
£¨..£©ÕâÀï¸ÃÊÇÑéÖ¤¸üУ¬¸üÐÂÇ°µÄidµÈÓÚ¸üкóµÄid,²¢ÇÒ¸üÐÂÇ°colµÄÖµÊÇ1£¬¸üкóµÄÖµÊÇ2
Ïà¹ØÎĵµ£º
±¾ÏµÁÐÎÄÕµ¼º½
[Oracle]¸ßЧµÄPL/SQL³ÌÐòÉè¼Æ(Ò»)--αÁÐROWNUMʹÓü¼ÇÉ
[Oracle]¸ßЧµÄPL/SQL³ÌÐòÉè¼Æ(¶þ)--±êÁ¿×Ó²éѯ
[Oracle]¸ßЧµÄPL/SQL³ÌÐòÉè¼Æ(Èý)--PackageµÄÓŵã
[Oracle]¸ßЧµÄPL/SQL³ÌÐòÉè¼Æ(ËÄ)--ÅúÁ¿´¦Àí
[Oracle]¸ßЧµÄPL/SQL³ÌÐòÉè¼Æ(Îå)--µ÷Óô洢¹ý³Ì·µ»Ø½á¹û¼¯
[Oracle]¸ßЧµÄPL/SQL³ÌÐòÉè¼Æ(Áù)- ......
1¡¢Ñ»·²åÈë²âÊÔÊý¾Ý£º
SQL>
declare
maxrecords constant int:=100;
i int :=1;
Begin
for i in 1..maxrecords loop
--²åÈëÊý¾Ý
Insert into TEST.EXAMPLE(name,phone,address) values('·ÖÒ³²âÊÔÊý¾Ý....','ÁªÏµµç»°','ÁªÏµµØÖ·');
end loop;
commit;
end;
´Ë´¦EXAMPLE±í¶¨ÒåΪ(ID number,name ......
ÔÚÑ°ÕÒPowerDesignerÏà¹ØÐÅÏ¢µÄʱºòżȻ·¢ÏÖµÄ.ʹÓÃtimestamp
΢ÈíMSDNÄÚÈÝ:
timestamp (Transact-SQL)
¹«¿ªÊý¾Ý¿âÖÐ×Ô¶¯Éú³ÉµÄΨһ¶þ½øÖÆÊý×ÖµÄÊý¾ÝÀàÐÍ¡£timestamp ͨ³£ÓÃ×÷¸ø±íÐмӰ汾´ÁµÄ»úÖÆ¡£ ´æ´¢´óСΪ 8 ¸ö×Ö½Ú¡£ timestamp Êý¾ÝÀàÐÍÖ»ÊǵÝÔöµÄÊý×Ö£¬²»±£ÁôÈÕÆÚ»òʱ¼ä¡£ ÈôÒª¼Ç¼ÈÕÆÚ»òʱ¼ä£¬ÇëʹÓà datetime ......
## ɾ³ýÊý¾Ý¿â
drop database ecport;
## ´´½¨Êý¾Ý¿â
create database ecport;
## ʹÓÃÊý¾Ý¿â
use ecport;
## ¹ú¼Ò±í½á¹¹
create table COUNTRY(
&nbs ......
Ìá¸ßSQLÖ´ÐÐЧÂʵļ¸µã½¨Òé:
¡¡¡¡¡ô¾¡Á¿²»ÒªÔÚwhereÖаüº¬×Ó²éѯ;
¡¡¡¡¹ØÓÚʱ¼äµÄ²éѯ£¬¾¡Á¿²»ÒªÐ´³É£ºwhere to_char(dif_date,'yyyy-mm-dd')=to_char('2007-07-01','yyyy-mm-dd');
¡¡¡¡¡ôÔÚ¹ýÂËÌõ¼þÖУ¬¿ÉÒÔ¹ýÂ˵ô×î´óÊýÁ¿¼Ç¼µÄÌõ¼þ±ØÐë·ÅÔÚwhere×Ó¾äµÄĩβ;
¡¡¡¡from×Ó¾äÖÐдÔÚ×îºóµÄ±í(»ù´¡±í£¬driving table)½«±»× ......