序列、同义词

 

创建序列

 

 

CREATE SEQUENCE myseq;  //创建序列
CREATE TABLE testseq(
next NUMBER,
curre NUMBER  //当前
)

 

 执行三次

--执行三次
INSERT INTO testseq(next,curre) VALUES(myseq.nextval,myseq.currval)
select * from testseq

 

 

 

 再次创建序列

 

DROP SEQUENCE myseq;
CREATE SEQUENCE lanpo INCREMENT BY 2;
select * from testseq

 

 

 执行几次

INSERT INTO testseq(next,curre) VALUES(lanpo.nextval,lanpo.currval)
select * from testseq

 

序列从指定的值开始

CREATE SEQUENCE lanpoo INCREMENT BY 2 START WITH 10;

 

插入五次

CREATE TABLE testseq2(
next NUMBER,
curre NUMBER
)

INSERT INTO testseq2(next,curre) VALUES(lanpoo.nextval,lanpoo.currval)

 

 

 

创建序列使其在1,3,5,7,9循环

CREATE SEQUENCE lanpo3 MAXVALUE 10  START WITH 1 INCREMENT BY 2 CACHE 2 CYCLE
;
CREATE TABLE testseq3(
next NUMBER,
curre NUMBER
)

 

 

INSERT INTO testseq3(next,curre) VALUES(lanpo3.nextval,lanpo3.currval)
select * from testseq3

 

 同义词（了解）

 

删除

注意：此种特性只适合oracle数据库