oracle中sequence使用的限制

在使用序列的currval和nextval时的限制 创建一个序列

create sequence test_seq minvalue 1 maxvalue 10000000 start with 1 increment by 1 cache 20;

在delete,select,update语句的子查询中不能使用sequence的值

SQL> delete from test_jy where test_id < (select test_seq.currval from dual); 
delete from test_jy where test_id <(select test_seq.currval from dual) 
ORA-02287: 此处不允许序号 

SQL> select * from test_jy where test_id < (select test_seq.currval from dual); 
select * from test_jy where test_id <(select test_seq.currval from dual) 
ORA-02287: 此处不允许序号 

SQL> update test_jy set test_id=0 where test_id < (select test_seq.currval from dual); 
update test_jy set test_id=0 where test_id <(select test_seq.currval from dual) 
ORA-02287: 此处不允许序号 

在查询视图或物化视图时

SQL> select a.* from test_v a where a.userid

带有distinct操作符的select语句不能使用

SQL> select distinct a.*,test_seq.currval from test_v a ; 
select distinct a.*,test_seq.currval from test_v a 
ORA-02287: 此处不允许序号 

有group by,order by操作的select语句不能使用

SQL> select test_jy.*,test_seq.currval from test_jy group by test_jy.test_id; 
select test_jy.*,test_seq.currval from test_jy group by test_jy.test_id 
ORA-02287: 此处不允许序号 

SQL> select test_jy.*,test_seq.currval from test_jy order by test_jy.test_id; 
select test_jy.*,test_seq.currval from test_jy order by test_jy.test_id 
ORA-02287: 此处不允许序号 

有UNION, INTERSECT, MINUS操作符的语句不能使用

 
SQL> select test_jy.*,test_seq.currval from test_jy where test_id=1 
2 union 
3 select test_jy.*,test_seq.currval from test_jy where test_id=2;
select test_jy.*,test_seq.currval from test_jy where test_id=1 
union 
select test_jy.*,test_seq.currval from test_jy where test_id=2 
ORA-02287: 此处不允许序号 

SQL> select test_jy.*,test_seq.currval from test_jy where test_id=1 
2 intersect 
3 select test_jy.*,test_seq.currval from test_jy where test_id=2; 
select test_jy.*,test_seq.currval from test_jy where test_id=1 
intersect 
select test_jy.*,test_seq.currval from test_jy where test_id=2 
ORA-02287: 此处不允许序号 

SQL> select test_jy.*,test_seq.currval from test_jy where test_id=1 
2 minus 
3 select test_jy.*,test_seq.currval from test_jy where test_id=2; 
select test_jy.*,test_seq.currval from test_jy where test_id=1 
minus 
select test_jy.*,test_seq.currval from test_jy where test_id=2 
ORA-02287: 此处不允许序号 

在select语句中的where子句中

SQL> select test_jy.* from test_jy where test_id

在create table或alter table语句的中default值是不能使用sequence

SQL> alter table test_jy modify test_id number(20) default test_seq.currval; 
alter table test_jy modify test_id number(20) default test_seq.currval 
ORA-00984: 列在此处不允许 

还有就在check约束中不能使用

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