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例子-给oracle添加自增长字段

fenglingwan 2020-08-21 22:23 381 查看 https://blog.51cto.com/1486146

--创建油箱标定表GasDemarcate

/*drop table GasDemarcate;
drop Sequence SEQ_GasDemarcate_ID;
drop TRIGGER Trig_Update_GasDemarcate_ID;
drop TRIGGER Trig_ProPri_GasDemarcate_ID;

select from GasDemarcate
insert into GasDemarcate(GASSIZEID)
values(15);
commit;
delete GasDemarcate/

/==============================================================/
/ Table: "GasDemarcate" /
/==============================================================/
create table GasDemarcate
(
ID INTEGER not null,
GASSIZEID INTEGER,
OILVALUE FLOAT,
SENSORVAL FLOAT,
constraint PK_GASDEMARCATE_ID primary key (ID)
);

comment on column GasDemarcate.ID is
'主键自增长ID';

comment on column GasDemarcate.GASSIZEID is
'对应GASSIZE表的ID';

comment on column GasDemarcate.OILVALUE is
'油量';

comment on column GasDemarcate.SENSORVAL is
'测量值(传感器值)';

--建序列
CREATE SEQUENCE SEQ_GasDemarcate_ID
INCREMENT BY 1
START WITH 1
MAXVALUE 1.0E28 MINVALUE 1 NOCYCLE
CACHE 50 NOORDER;

--建自动更新的触发器
CREATE OR REPLACE TRIGGER Trig_Update_GasDemarcate_ID
BEFORE INSERT
ON GasDemarcate
FOR EACH ROW
DECLARE
next_id NUMBER;
BEGIN
--Get the next id number from the sequence
SELECT SEQ_GasDemarcate_ID.NEXTVAL
INTO next_id
FROM dual;
--Use the sequence number as the primary key
--for the record being inserted.
:new.id := next_id;
END;

--要选中下面的单独执行!!!!!!!

--建保护 PRIMARY KEY 的触发器
CREATE OR REPLACE TRIGGER Trig_ProPri_GasDemarcate_ID
BEFORE UPDATE OF ID ON GasDemarcate
FOR EACH ROW
BEGIN
RAISE_APPLICATION_ERROR (-20000,
'Trig_ProPri_GasDemarcate_ID : Updates of the ID field'
|| 'are not allowed. ');
END;

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