Oracle常遇问题解析26

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116. 两个结果集互加的函数?  
sql>select * from bsempms_old intersect select * from bsempms_new;  
9 J/ G- c1 t3 `sql>select * from bsempms_old union select * from bsempms_new;  
" k, Q. S7 E5 }) W8 L5 S; e& tsql>select * from bsempms_old union all select * from bsempms_new;  
# e8 [4 ?1 W5 H- e3 \0 C& m0 U$ s* ~8 {  
117. 两个结果集互减的函数?  
! Q* j8 E8 ?& }8 X+ p8 f6 jsql>select * from bsempms_old minus select * from bsempms_new;  
' L% s1 D7 ^: R- Y0 q1 x  
6 f' G3 |9 J# T: A1 p4 G* D118. 如何配置sequence?  
建sequence seq_custid  
create sequence seq_custid start 1 incrememt by 1;  
建表时:  
create table cust  
3 g3 C: f. s$ I7 A& r{ cust_id smallint not null,  
5 n- [7 m6 @, B/ J" W& F  W...}  
insert 时:  
6 Q" l# v* V4 N, s! Y* c( Jinsert into table cust  
: H0 @) {+ u  c0 [: Evalues( seq_cust.nextval, ...)  
  
9 v; X* w7 o6 C" f日期的各部分的常用的的写法  
2 G! \! f) {8 `; h, T5 D* Y" j119>.取时间点的年份的写法:  
- u* i# ~2 l& q! t, gselect to_char(sys2003-10-17,’yyyy’) from dual;  
! O, j/ [5 V& f* p9 f( ?+ M0 C  
* L, l, c- h+ @) Y/ ?0 M& k" n! K120>.取时间点的月份的写法:  
: A, {4 [$ r3 R$ `& Rselect to_char(sys2003-10-17,’mm’) from dual;