update a set a.VAC74=b.VAA03,a.VAC75=b.VAA05,a.VAC76=b.ABW01
  ,a.VAC77=b.VAA15,a.VAC78=b.VAA12
from VAC1 a
join VAA1 b on b.VAA01=a.VAA01
where isnull(a.VAC74,'') <= ''

update a set a.VAE94=b.VAA04,a.VAE95=b.VAA05,a.VAE96=b.ABW01
  ,a.VAE98=b.VAA15,a.VAE97=b.VAA12
from VAE1 a
join VAA1 b on b.VAA01=a.VAA01
where isnull(a.VAE94,'') <= ''