SELECT
to_number( to_date(to_char(b.FBIZDATE, 'yyyy-mm-dd'), 'yyyy-mm-dd')-to_date(to_char(a.FBIZDATE, 'yyyy-mm-dd'), 'yyyy-mm-dd' ) )
day
FROM
CT_BB_BreedingBatchManage a
INNER JOIN CT_D_InternalReceive b ON a.fid = b.CFBATCHNOID