sql查重复数据并删除

测试数据环境是pg库

第一步查出重复数据：

SELECT zjddm,count(zjddm) as cnt from zjdly GROUP BY zjddm HAVING count(zjddm)>1

第二步删除重复数据：

DELETE from zjdly where zjddm in (SELECT zjddm from zjdly GROUP BY zjddm HAVING count(zjddm)>1)