根据表的某个字段删除重复

<delete id="deleterepeat" parameterType="com.glxcn.mybatis.model.TO7xzRecord">

DELETE FROM t_o7xz_record

WHERE id NOT IN (

SELECT*

  FROM (

SELECTmin(id)

FROM

t_o7xz_record

GROUP BY

appname

HAVING

count(*) > 1

) a

)

AND appname IN (

SELECT*

  FROM (

SELECT appname

FROM t_o7xz_record

GROUP BY

appname

HAVING

count(*) > 1

) b

);

</delete>

appname是不允许重复的字段，t_o7xz_record是表