思路1:使用序列
创建序列:
CREATE SEQUENCE seq_name
INCREMENT BY 1
START WITH 1
MINVALUE 1
MAXVALUE 999999999
CYCLE
NOORDER
CACHE 50
/
使用序列:
SELECT LTRIM(TO_CHAR(seq_name.NEXTVAL,'000000000')) INTO v_var FROM DUAL;思路2: 建一张表id_tb存储 最大序号
插入数据时
SELECT ID INTO V_ID FROM ID_TB WHERE ROWNUM = 1 FOR UPDATE;
INSERT INTO TABLE_NAME(ID,...) VALUES(V_ID,...);
UPDATE SET ID_TB ID = ID+1;
COMMIT;
创建序列:
CREATE SEQUENCE seq_name
INCREMENT BY 1
START WITH 1
MINVALUE 1
MAXVALUE 999999999
CYCLE
NOORDER
CACHE 50
/
使用序列:
SELECT LTRIM(TO_CHAR(seq_name.NEXTVAL,'000000000')) INTO v_var FROM DUAL;思路2: 建一张表id_tb存储 最大序号
插入数据时
SELECT ID INTO V_ID FROM ID_TB WHERE ROWNUM = 1 FOR UPDATE;
INSERT INTO TABLE_NAME(ID,...) VALUES(V_ID,...);
UPDATE SET ID_TB ID = ID+1;
COMMIT;
就很难达到自动编号的目的了。MAX(ID)+1 能行吗?
ORACLE一般的做法是同时使用序列和触发器来生成一个自增字段.
CREATE SEQUENCE SEQname
INCREMENT BY 1
START WITH 1
MAXVALUE 99999999
/
CREATE TRIGGER TRGname
BEFORE INSERT ON table_name
REFERENCING
NEW AS :NEW
FOR EACH ROW
Begin
SELECT SEQname.NEXTVAL
INTO :NEW.FIELDname
FROM DUAL;
End;(2)第二种方法:
CREATE OR REPLACE TRIGGER TR1
BEFORE INSERT ON temp_table
FOR EACH ROW
declare
com_num NUMBER;
BEGIN
SELECT MAX(ID) INTO COM_NUM FROM TEMP_TABLE;
:NEW.ID:=COM_NUM+1;
END TR1;