DB2
CREATE
TABLE
T1
(
id
INTEGER
NOT
NULL
GENERATED ALWAYS
AS
IDENTITY
(START
WITH
1
INCREMENT
BY
1
MINVALUE
1
NO MAXVALUE NO CYCLE NO CACHE
ORDER
),
...
);
Oracle(需要創建一個SEQUENCE和一個TRIGGER):
CREATE TABLE T1
(
id NUMBER(10,0) NOT NULL,
...
);
CREATE SEQUENCE T1_ID_SEQ INCREMENT BY 1 START WITH 1 NOMAXVALUE NOCYCLE CACHE 100 ORDER;
CREATE OR REPLACE TRIGGER INSERT_T1_ID
BEFORE INSERT ON T1
REFERENCING NEW AS new OLD AS old
FOR EACH ROW
BEGIN
SELECT T1_ID_SEQ.NEXTVAL INTO :new.id FROM DUAL;
END;
/
MySQL
CREATE TABLE T1
(
id INT NOT NULL AUTO_INCREMENT,
...
);
PostgreSQL
CREATE TABLE T1
(
id SERIAL NOT NULL,
...
);
SQL Server
CREATE TABLE T1
(
id INT NOT NULL IDENTITY,
...
);
Sybase
CREATE TABLE T1
(
id INT NOT NULL IDENTITY,
...
);





Oracle(需要創建一個SEQUENCE和一個TRIGGER):














MySQL





PostgreSQL





SQL Server





Sybase




