ORACLE ORDER BYÓ÷¨×ܽá
½ñÌìÔÚ¹äÂÛ̳µÄʱºò¿´µ½shiyiwanͬѧдÁËÒ»¸öºÜ¼òµ¥µÄÓï¾ä£¬¿ÉÊÇorder byºóÃæµÄÐÎʽȴ±È½ÏÐÂÓ±£¨¶ÔÓÚÎÒÀ´ËµÅ¶£©£¬ÒÔÇ°´ÓÀ´Ã»¿´¹ýÕâÖÖÓ÷¨£¬¾ÍÏë¼ÇÏÂÀ´£¬ÕýºÃ×ܽáÒ»ÏÂORDER BYµÄ֪ʶ¡£
1¡¢ORDER BY ÖйØÓÚNULLµÄ´¦Àí
ȱʡ´¦Àí£¬OracleÔÚOrder by ʱÈÏΪnullÊÇ×î´óÖµ£¬ËùÒÔÈç¹ûÊÇASCÉýÐòÔòÅÅÔÚ×îºó£¬DESC½µÐòÔòÅÅÔÚ×îÇ°¡£
µ±È»£¬ÄãÒ²¿ÉÒÔʹÓÃnulls first »òÕßnulls last Óï·¨À´¿ØÖÆNULLµÄλÖá£
Nulls firstºÍnulls lastÊÇOracle Order byÖ§³ÖµÄÓï·¨
Èç¹ûOrder by ÖÐÖ¸¶¨Á˱í´ïʽNulls firstÔò±íʾnullÖµµÄ¼Ç¼½«ÅÅÔÚ×îÇ°(²»¹ÜÊÇasc »¹ÊÇ desc)
Èç¹ûOrder by ÖÐÖ¸¶¨Á˱í´ïʽNulls lastÔò±íʾnullÖµµÄ¼Ç¼½«ÅÅÔÚ×îºó (²»¹ÜÊÇasc »¹ÊÇ desc)
ʹÓÃÓï·¨ÈçÏ£º
--½«nullsʼÖÕ·ÅÔÚ×îÇ°
select * from zl_cbqc order by cb_ld nulls first
--½«nullsʼÖÕ·ÅÔÚ×îºó
select * from zl_cbqc order by cb_ld desc nulls last
2¡¢¼¸ÖÖÅÅÐòµÄд·¨
µ¥ÁÐÉýÐò£ºselect<column_name> from <table_name> order by <column_name>; £¨Ä¬ÈÏÉýÐò£¬¼´Ê¹²»Ð´ASC£©
µ¥ÁнµÐò£ºselect <column_name> from <table_name> order by <column_name> desc;
¶àÁÐÉýÐò£ºselect <column_one>, <column_two> from <table_name> order by <column_one>, <column_two>;
¶àÁнµÐò£ºselect <column_one>, <column_two> from <table_name> order by <column_one> desc, <column_two> desc;
¶àÁлìºÏÅÅÐò£ºselect <column_one>, <column_two> from <table_name> order by <column_one> desc, <column_two> asc;
3¡¢½ñÌì¿´µ½µÄÐÂд·¨
SQL> select * from tb;
BLOGID BLOGCLASS
---------- ------------------------------
1 ÈËÉú
2 ѧϰ
3 ¹¤×÷
5 ÅóÓÑ
SQL> select * from tb order by decode(blogid,3,1,2), blogid;
BLOGID BLOGCLASS
---------- ------------------------------
3 ¹¤×÷
1 ÈËÉú
2 ѧϰ
5 ÅóÓÑ
ÎÒËù˵µÄ¾ÍÊÇÉÏÃæºìÉ«µ
Ïà¹ØÎĵµ£º
×÷Õߣº ÈÕÆÚ£º2005-12-8 1:43:32 À´Ô´£ºInternet µã»÷£º´Î ÆÀÂÛ
¡¡¡¡±¾ÎÄÖ»ÌÖÂÛOracleÖÐ×î³£¼ûµÄË÷Òý£¬¼´ÊÇB-treeË÷Òý¡£±¾ÎÄÖÐÉæ¼°µÄÊý¾Ý¿â°æ±¾ÊÇOracle8i¡£
¡¡¡¡Ò». ²é¿´ÏµÍ³±íÖеÄÓû§Ë÷Òý
¡¡¡¡ÔÚOracleÖУ¬SYSTEM±íÊÇ°²×°Êý¾Ý¿âʱ×Ô¶¯½¨Á¢µÄ£¬Ëü°üº¬Êý¾Ý¿âµÄÈ«²¿Êý¾ ......
select sysdate from dual; ´Óα±í²éϵͳʱ¼ä£¬ÒÔĬÈϸñʽÊä³ö¡£
sysdate+(5/24/60/60) ÔÚϵͳʱ¼ä»ù´¡ÉÏÑÓ³Ù5Ãë
sysdate+5/24/60 ÔÚϵͳʱ¼ä»ù´¡ÉÏÑÓ³Ù5·ÖÖÓ
sysdate+5/24 ÔÚϵͳʱ¼ä»ù´¡ÉÏÑÓ³Ù5Сʱ
sysdate+5 ÔÚϵͳʱ¼ä»ù´¡ÉÏÑÓ³Ù5Ìì
ËùÒÔÈÕÆÚ¼ÆËãĬÈϵ¥Î»ÊÇÌì
round (sysdate,’day’) ²»ÊÇËijý ......
Ŀ¼
======================================================
1.ʹÓÃrownumΪ¼Ç¼ÅÅÃû
2.ʹÓ÷ÖÎöº¯ÊýÀ´Îª¼Ç¼ÅÅÃû
3.ʹÓ÷ÖÎöº¯ÊýΪ¼Ç¼½øÐзÖ×éÅÅÃû
Ò»¡¢Ê¹ÓÃrownumΪ¼Ç¼ÅÅÃû£º
¡¾1¡¿²âÊÔ»·¾³£º
SQL> desc user_order;
Name   ......
oracleÖÐÁ¬½ÓÓë»á»°²»ÊÇÒ»¸ö¸ÅÄî!!!
ÔÚOracleÖУ¬Á¬½ÓÖ»ÊÇ¿Í»§½ø³ÌºÍÊý¾Ý¿âʵÀýÖ®¼äµÄÒ»ÌõÌØÊâÏß·£¬×î³£¼ûµÄ¾ÍÊÇÍøÂçÁ¬½Ó¡£ÕâÌõÁ¬½Ó¿ÉÄÜÁ¬½Óµ½Ò»¸öרÓ÷þÎñÆ÷½ø³Ì£¬Ò²¿ÉÄÜÁ¬½Óµ½µ÷¶ÈÆ÷¡£ÈçÇ°ËùÊö£¬Á¬½ÓÉÏ¿ÉÒÔÓÐ0¸ö»ò¶à¸ö»á»°£¬Õâ˵Ã÷¿ÉÒÔÓÐÁ¬½Ó¶øÎÞÏàÓ¦µÄ»á»°¡£ÁíÍ⣬һ¸ö»á»°¿ÉÒÔÓÐÁ¬½ÓÒ²¿ÉÒÔûÓÐÁ¬½Ó¡£Ê¹Óø߼¶Oracle N ......