常用数据库的自增字段创建方法汇总

 

DB2

CREATE TABLE T1
(
id INTEGER NOT NULL GENERATEDALWAYS AS IDENTITY (START WITH 1 INCREMENT BY 1 MINVALUE 1 NOMAXVALUENOCYCLENOCACHE ORDER ),
...
);

Oracle （需要创建一个SEQUENCE和一个TRIGGER）：

CREATE TABLE T1
(
id NUMBER ( 10 , 0 ) NOT NULL ,
...
);
CREATE SEQUENCET1_ID_SEQINCREMENT BY 1 START WITH 1 NOMAXVALUENOCYCLECACHE 100 ORDER ;
CREATE OR REPLACE TRIGGER INSERT_T1_ID
BEFORE INSERT ON T1
REFERENCINGNEW AS newOLD AS old
FOR EACHROW
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
(
idSERIAL NOT NULL ,
...
);

SQL Server

CREATE TABLE T1
(
id INT NOT NULL IDENTITY ,
...
);

Sybase

CREATE TABLE T1
(
id INT NOT NULL IDENTITY ,
...
);