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

Ëæ»úÑ¡ÔñÐеÄSQLÓï¾ä? ORACLE SQLSERVER ECT.

MySQL:
SELECT column from table
ORDER BY RAND()
LIMIT 1
PostgreSQL:
SELECT column from table
ORDER BY RANDOM()
LIMIT 1
Microsoft SQL Server:
SELECT TOP 1 column from table
ORDER BY NEWID()
IBM DB2
SELECT column, RAND() as IDX
from table
ORDER BY IDX FETCH FIRST 1 ROWS ONLY
Thanks Tim
Oracle:
SELECT column from
( SELECT column from table
ORDER BY dbms_random.value )
WHERE rownum = 1
Thanks Mark Murphy
Feel free to post other example, variations, and SQL statements for other database servers in the comments.


Ïà¹ØÎĵµ£º

Á½¸ö¾­µäµÄOracle´¥·¢Æ÷ʾÀý

¡¾°¸ÀýÒ»¡¿
ÌâÄ¿£º
--´¥·¢Æ÷£º
--Ìí¼ÓÔ±¹¤ÐÅÏ¢,Á÷Ë®ºÅ×÷Ϊ×Ô¶¯±àºÅ(ͨ¹ýÐòÁÐÉú³É),
--²¢ÇÒÅжÏÈç¹û¹¤×ÊСÓÚ0,Ôò¸ÄΪ0;Èç¹û´óÓÚ10000,Ôò¸ÄΪ10000¡£
CREATE TABLE emp2(
e_id NUMBER,
e_no NUMBER,
e_name VARCHAR2(20),
e_sal NUMBER
)
SELECT * from emp2;
CREATE SEQUENCE seq_trg_id;
INSERT INTO emp2(e_i ......

µÇ¼oracleÊý¾Ý¿âʱ³£ÓõIJÙ×÷ÃüÁîÕûÀí

¼oracleÊý¾Ý¿âʱ³£ÓõIJÙ×÷ÃüÁîÕûÀí
1¡¢su – oracle ²»ÊDZØÐ裬ÊʺÏÓÚûÓÐDBAÃÜÂëʱʹÓ㬿ÉÒÔ²»ÓÃÃÜÂëÀ´½øÈësqlplus½çÃæ¡£
2¡¢sqlplus /nolog »òsqlplus system/manager »ò./sqlplus system/manager@ora9i;
3¡¢SQL>connect / as sysdba ;£¨as sysoper£©»ò
connect internal/oracle AS SYSDBA ;(scott/tiger) ......

oracleÊý¾Ý¿â´æ´¢

select * from test where rownum <=10 ÏÂÃæÊǹØÓÚrownumµÄ½éÉÜ ================================ RownumºÍrow_number() over()µÄʹÓà ROWNUMÊÇOracle´Ó8¿ªÊ¼ÌṩµÄÒ»¸öαÁУ¬ÊǰÑSQL³öÀ´µÄ½á¹û½øÐбàºÅ£¬Ê¼ÖÕ´Ó1¿ªÊ¼£¬³£¼ûµÄÓÃ;¾ÍÊÇÓÃÀ´·ÖÒ³Êä³ö. ±ÈÈç SELECT * from torderdetail a WHERE ROWNUM <= 10 ÕâÌõÓï¾ä¾ ......

½éÉÜSQL Server 2005µÄCROSS Apply

Cross Applyʹ±í¿ÉÒԺͱíÖµº¯Êý½á¹û½øÐÐjoin, ÕâÑù±íÖµº¯ÊýµÄ²ÎÊý¾Í¿ÉÒÔʹÓÃÒ»¸ö½á¹û¼¯£¬¶ø²»ÊÇÒ»¸ö±êÁ¿Öµ£¬ÏÂÃæÊÇbook onlineµÄÔ­ÎÄ£¬ÓÐÀý×Ó£¬ÓнâÊÍ¡£
The APPLY operator allows you to invoke a table-valued function for each row returned by an outer table expression of a query. The table-valued function act ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ