SQL筆記——記錄一下學習的sql語句

update

聯表更新

UPDATE basicinfo SET basicinfo.zgh=(SELECT personnel.zgh FROM personnel WHERE basicinfo.xm=personnel.xm AND basicinfo.dw=personnel.dw LIMIT 1)

select

查詢重複項

SELECT * FROM basicinfo WHERE zgh in (SELECT zgh FROM basicinfo GROUP BY zgh HAVING COUNT(zgh)>1)