>  delete from TBL2,TBL1
>  where TBL2.ID == TBL1.ID
>    and TBL1.MID == 'target';

delete tbl2.*,tbl1.* from tbl2 left join tbl1 on  TBL2.ID = TBL1.ID
where  TBL1.MID = 'target';

やってないから自信ないけど
こんな書き方は通らないでしょうか

楠吉彦　もあでぶ　moredebu
email: moredebu@xxxxxxxxxx
Homepage: http://www.my-drug.com