需求:
有一张表已经存在数据库,但是没有主键,没有自增列,导致做修改等操作的时候较为繁琐,现在要修改其ID列为自增(填充数据)
修改之前:
修改之后:
方法:
1.复制表结构
2.若无自增字段,先增加自增id字段
3.创建触发器
4.将老数据转移到新的表
5.删除原表,将新表改名
CREATE TABLE TEST1 AS SELECT * FROM REPAIR_FACTORY WHERE 1<>1
ALTER TABLE "TEST1" ADD ID NUMBER
ALTER TABLE "TEST1" ADD PRIMARY KEY ("ID");
DROP TRIGGER TRG_BEFORE_INSERT_TEST1
CREATE TRIGGER TRG_BEFORE_INSERT_TEST1 BEFORE INSERT ON TEST1
FOR EACH ROW
BEGIN
SELECT
SEQ_REPAIR_FACTORY_ID.NEXTVAL INTO :NEW.ID
FROM
DUAL ;
END ;
INSERT INTO TEST1("NAME", "PROVINCE", "CITY","CODE","PERSON","FORM","RIQI","MONEY","ADD