oracle 请问一下,一张已经建好的表,怎样在其中一列上添加自增列???新 ...
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发布时间：2022-04-26 13:30
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时间：2022-04-10 02:50
DROP SEQUENCE _SEQUENCE;
CREATE SEQUENCE _SEQUENCE
START WITH 1000
MAXVALUE 99999999
MINVALUE 1
NOCYCLE
NOCACHE
ORDER;
再建一个trigger：
DROP TRIGGER _TRIGGER;
CREATE OR REPLACE TRIGGER _TRIGGER
BEFORE INSERT
ON tablename FOR EACH ROW
DECLARE
nextid NUMBER;
BEGIN
IF :new.UserID IS NULL OR :new.UserID = 0
THEN
SELECT _SEQUENCE.NEXTVAL INTO nextid FROM sys.DUAL;
:new.UserID := nextid;
END IF;
END _TRIGGER;
/
