Sql Merge语句插入行,但不更新
我对MERGE语句有问题。行未按应有的方式更新,旧行将再次插入。下面是一个使用HR模式的简单示例代码:Sql Merge语句插入行,但不更新,sql,oracle,Sql,Oracle,我对MERGE语句有问题。行未按应有的方式更新,旧行将再次插入。下面是一个使用HR模式的简单示例代码: --CREATES A SEQUENCE FOR A HISTORY TABLE CREATE SEQUENCE JOBHIS_SEQ START WITH 1 INCREMENT BY 1 MINVALUE 1 MAXVALUE 999999999999999999999999999 NOCACHE NOORDER NOCYCLE; --CREATES A HISTORY
--CREATES A SEQUENCE FOR A HISTORY TABLE
CREATE SEQUENCE JOBHIS_SEQ
START WITH 1
INCREMENT BY 1
MINVALUE 1
MAXVALUE 999999999999999999999999999
NOCACHE
NOORDER
NOCYCLE;
--CREATES A HISTORY TABLE
CREATE TABLE JOBHIS (
ID NUMBER(10) NOT NULL,
LOAD_DATE DATE,
JOB_ID VARCHAR2(10) NOT NULL ENABLE,
JOB_TITLE VARCHAR2(35) NOT NULL ENABLE,
MIN_SALARY NUMBER(6,0),
MAX_SALARY NUMBER(6,0),
CONSTRAINT JOBHIS_ID_PK PRIMARY KEY (ID) ENABLE
)
--this inserts 19 rows into jobhis
MERGE INTO JOBHIS JH
USING ( SELECT SYSDATE AS LOAD_DATE, JOB_ID, JOB_TITLE, MIN_SALARY, MAX_SALARY
FROM JOBS
) J
ON (JH.JOB_ID = J.JOB_ID AND JH.LOAD_DATE = J.LOAD_DATE)
WHEN MATCHED THEN UPDATE SET JH.MIN_SALARY = J.MIN_SALARY
WHERE JH.MIN_SALARY != J.MIN_SALARY
WHEN NOT MATCHED THEN INSERT (JH.ID, JH.LOAD_DATE, JH.JOB_ID, JH.JOB_TITLE, JH.MIN_SALARY, JH.MAX_SALARY)
VALUES(JOBHIS_SEQ.NEXTVAL, SYSDATE, J.JOB_ID, J.JOB_TITLE, J.MIN_SALARY, J.MAX_SALARY)
--lets update jobs to get a row update into jobhis
UPDATE JOBS
SET MIN_SALARY = 10000
WHERE JOB_ID = 'AC_ACCOUNT'
--lets merge again
MERGE INTO JOBHIS JH
USING ( SELECT SYSDATE AS LOAD_DATE, JOB_ID, JOB_TITLE, MIN_SALARY, MAX_SALARY
FROM JOBS
) J
ON (JH.JOB_ID = J.JOB_ID AND JH.LOAD_DATE = J.LOAD_DATE)
WHEN MATCHED THEN UPDATE SET JH.MIN_SALARY = J.MIN_SALARY
WHERE JH.MIN_SALARY != J.MIN_SALARY
WHEN NOT MATCHED THEN INSERT (JH.ID, JH.LOAD_DATE, JH.JOB_ID, JH.JOB_TITLE, JH.MIN_SALARY, JH.MAX_SALARY)
VALUES(JOBHIS_SEQ.NEXTVAL, SYSDATE, J.JOB_ID, J.JOB_TITLE, J.MIN_SALARY, J.MAX_SALARY)
--> 19 rows are inserted, no updates, why? Somehow LOAD_DATE does not seem to work
--lets update jobs to back its original state
UPDATE JOBS
SET MIN_SALARY = 4200
WHERE JOB_ID = 'AC_ACCOUNT'
我已启用自动提交,因此这些语句已提交。尝试在trunc(JH.LOAD\u DATE)=trunc(J.LOAD\u DATE)
每次尝试更新时,您都会有不同的sysdate,因为您正在执行selectsysdateload\u Date。。。从子查询中的作业
,这将与历史记录表中的日期不匹配
选中此项,它将与trunc一起工作尝试在trunc(JH.LOAD\u DATE)=trunc(J.LOAD\u DATE)
每次尝试更新时,您都会有不同的sysdate,因为您正在执行selectsysdateload\u Date。。。从子查询中的作业
,这将与历史记录表中的日期不匹配
选中此项,它将与trunc一起工作谢谢,是的,这就是原因!谢谢,是的,这就是原因!