sql 1 to 1 relationship table setup -

sql 1 to 1 relationship table setup -

if have parent item report, called study , each study has 1 supreporta, subreportb , subreportc. , each subreport belongs 1 report, 1 1 relationship, should set tables study table having

study ------- id subreportaid subreportbid subreportcid

or should set tables each subreport has study id

subreporta ----------- id reportid subreportb ---------- id reportid subreportc ---------- id reportcid

which way best practice , why? help in advance....

since have role 1 study has 1 type of each sub study , vice-versa right model be:

table report

report id pk

table subreport

subreport id pk idreport (fk->report) idtypesubreport (fk->typesubreport) (add unique id,idreport)

and table typesubreport

typesubreport id description

this way not have duplicated info anywhere.

hope helps.

sql