I may be completely off course from where you want to get to but...select
t1.TAU_UID,
min(t1.TAU_LAST_UPDATE_DATE) TAU_LAST_UPDATE_DATE
from
TAU_TREATMENT_AUTHORIZATION t1
where
exists (select *
from TAU_TREATMENT_AUTHORIZATION t2
where t1.TAU_UID = t2.TAU_UID
and t2.TAU_LAST_UPDATE_DATE is null
)
group by t1.TAU_UIDDoes this get you there?
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There are two kinds of light -- the glow that illuminates, and the glare that obscures. -James Thurber