@如何建立一个自动增加字段?
1、建立表:
CREATE TABLE checkup_history(
CHECKUP_NO NUMBER(10,0) NOT NULL,
ID_NO NUMBER(10,0),
CHECKUP_TYPE VARCHAR2(30),
CHECKUP_DATE DATE,
DOCTOR_NAME VARCHAR2(50)
);
2、建立序列:
CREATE SEQUENCE checkup_no_seq
NOCYCLE
MAXVALUE 9999999999
START WITH 2;3、建立触发器:
CREATE OR REPLACE TRIGGER set_checkup_no
BEFORE INSERT ON checkup_history
FOR EACH ROW
DECLARE
next_checkup_no NUMBER;
BEGIN
--Get the next checkup number from the sequence
SELECT checkup_no_seq.NEXTVAL
INTO next_checkup_no
FROM dual;
--use the sequence number as the primary key
--for the record being inserted
:new.checkup_no := next_checkup_no;
END;
1、建立表:
CREATE TABLE checkup_history(
CHECKUP_NO NUMBER(10,0) NOT NULL,
ID_NO NUMBER(10,0),
CHECKUP_TYPE VARCHAR2(30),
CHECKUP_DATE DATE,
DOCTOR_NAME VARCHAR2(50)
);
2、建立序列:
CREATE SEQUENCE checkup_no_seq
NOCYCLE
MAXVALUE 9999999999
START WITH 2;3、建立触发器:
CREATE OR REPLACE TRIGGER set_checkup_no
BEFORE INSERT ON checkup_history
FOR EACH ROW
DECLARE
next_checkup_no NUMBER;
BEGIN
--Get the next checkup number from the sequence
SELECT checkup_no_seq.NEXTVAL
INTO next_checkup_no
FROM dual;
--use the sequence number as the primary key
--for the record being inserted
:new.checkup_no := next_checkup_no;
END;
before insert on test
for each row
declare
-- local variables here
begin
update a set status=0 where status=1;
end TEST_UPDATE_TRI;