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oracleÖУ¬
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create table device
(
 id number(10) not null primary key,
 dept varchar2(50)  not null
)
tablespace users
/
 
Òª½«dept×ֶθüгÉÈçÏÂÄÚÈÝ£ºselect * from message where name='tom'
ÎÒÊÔ¹ýʹÓÃÈçϵĸüÐÂÓï¾ä²»ÐУºupdate device set dept='select * from message where name='tom' ' ;
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      update device set dept='select * from message where name=' 'tom' '  where  id=3' ;
 
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oracleÊ÷ÖÐpriorµÄÓ÷¨

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create table dept(deptno number,deptname varchar2(20),mgrno number);
insert into dept values (1, '×ܹ«Ë¾', null);
insert into dept values (2, 'Õã½­·Ö¹«Ë¾', 1);
insert into dept values (3, 'º¼ÖÝ·Ö¹«Ë¾', 2);
commit;
select t.* from dept t;
      DEPTNO &n ......

Oracle 30¸öhint

ÔÚSQLÓï¾äÓÅ»¯¹ý³ÌÖУ¬¾­³£»áÓõ½hint,
ÒÔÏÂÊÇÔÚSQLÓÅ»¯¹ý³ÌÖг£¼ûOracleÖÐ"HINT"µÄ30¸öÓ÷¨1. /*+ALL_ROWS*/
±íÃ÷¶ÔÓï¾ä¿éÑ¡Ôñ»ùÓÚ¿ªÏúµÄÓÅ»¯·½·¨,²¢»ñµÃ×î¼ÑÍÌÍÂÁ¿,ʹ×ÊÔ´ÏûºÄ×îС»¯.
ÀýÈç:
SELECT /*+ALL+_ROWS*/ EMP_NO,EMP_NAM,DAT_IN from BSEMPMS WHERE EMP_NO='SCOTT';
2. /*+FIRST_ROWS*/
±íÃ÷¶ÔÓï¾ä¿éÑ¡Ôñ ......

dz̸OracleÊý¾Ý¿âSCNºÅ

OracleÊý¾Ý¿âSCNºÅÏê½â:
¡¡¡¡ÏµÍ³¼ì²éµãscn(v$database(checkpoint_change#))
¡¡¡¡Êý¾ÝÎļþ¼ì²éµã(v$datafile(checkpoint_change#))
¡¡¡¡Êý¾ÝÎļþÖÕÖ¹scn(v$datafile(last_change#))
¡¡¡¡Êý¾ÝÎļþÖдæ·ÅµÄ¼ì²éµã
¡¡¡¡Æô¶¯scn (v$datafile_header(checkpoint_change#)
¡¡¡¡1¡¢ÏµÍ³¼ì²éµãscn
¡¡¡¡µ±Ò»¸ö¼ì²éµã¶¯×÷Íê³ ......

Oracle,MySQL,MSSQL ServerºÍAccessÊý¾Ý¿âµÄͳ¼Æº¯Êý

Oracle,MySQL,MSSQL ServerºÍAccessÊý¾Ý¿âµÄͳ¼Æº¯Êý
ÎÒÃÇÔÚ±à³ÌÖг£ÓõÄͳ¼Æº¯ÊýÓмÆÊý,ÇóºÍ,Çó×î´óÖµ,Çó×îСֵ,Ç󯽾ù,·½²îºÍ±ê×¼²î.
·½²î(Variance)
·½²îÊDZê׼ƫ²îµÄƽ·½¡£×éÖеÄÖµ£¬ÓëËüÃÇÆ½¾ùÖµÖ®¼äÆ«Àë³Ì¶ÈµÄ¶ÈÁ¿¡£
±ê׼ƫ²î(Standard Deviation)
Ò»¸ö²ÎÊý£¬Ö¸³öÒ»ÖÖ·½Ê½£¬Ò»¸ö¸ÅÂʺ¯ÊýÒÔÕâÖÖ·½Ê½·Ö²¼ÔÚÆ½¾ùÖµ¸ ......

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