mysql查找有某列但没有此列索引的表

select a.TABLE_SCHEMA,a.TABLE_NAME from information_schema.`COLUMNS` a left join (select 'etl_stamp' COLUMN_NAME ) b on a.COLUMN_NAME=b.COLUMN_NAME
left join information_schema.STATISTICS c on a.TABLE_SCHEMA=c.TABLE_SCHEMA and a.TABLE_NAME=c.TABLE_NAME and a.COLUMN_NAME=c.COLUMN_NAME
where a.TABLE_SCHEMA in ('db1','db2','db3') and b.COLUMN_NAME is not null and c.SEQ_IN_INDEX is null