sql server - How can I enforce this relationship? (Formerley: Is there a name for this type of database structure?) -


update 05/15/2013 understanding of problem has changed such "title" doesn't match anymore. should close , start new post? (what proper way handle edit in stackoverflow community?).

with following basic table structure, how can enforce relationship user can member of group, if user , group both related same tenant?

entities:

  • tenants:

    • id
    • name

  • user

    • id
    • fktenantid
    • name

  • groups

    • id
    • fktenantid
    • name

  • usersingroup

    • fkuserid
    • fkgroupid

for example:

i add 2 tenants:

id: name

1: tenanta

2: tenantb

i add 1 group each tenant:

id: tenantid: name

1: 1: groupa

2: 2: groupb

i add 1 user tenanta having id of 1:

id: tenantid: username

1: 1: usera

how can restrict can not add usera groupb.

if create table usersingroups columns fkuserid, fkgroupid, can't think of way constrain record 1:2 considered invalid.

thanks!

steve

with further research found post answers mine.

composite foreign key multiple related tables


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