If I understand this correctly, I think you want to implement the sort of security that Veil provides. Take a look at http://pgfoundry.org/projects/veil/ The documentation is at http://veil.projects.postgresql.org/curdocs/index.html __ Marc On Sun, 2006-01-01 at 17:02 -0400, littlebutty wrote: > Date: 22 Dec 2005 17:04:30 -0800 > From: "littlebutty" <littlebutty@xxxxxxxxx> > To: pgsql-general@xxxxxxxxxxxxxx > Subject: bit/integer operations in postgres > Message-ID: <1135299870.165441.317110@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> > > Does anyone know how I can solve this problem in Postgres: > > I am creating a table of user permissions. I want to represent each > permission as a bit location. Each new permission I add to my system > would be assigned to the next available bit (or column if you will) > That way I can simply turn on a particular bit location for a > particular user and then AND their permission level with a particular > permission bit. > Just as an example: > Access to financial data is the first bit and would be represented by > 1. > Access to the admin section would be the 2nd bit, represented by 01. > Access to the reporting section would be the 3rd bit, represented by > 001. > > Thus a user with access to the admin section but nothing else would > have 010 > and a user with access to everything would have 111. > > > All possible permissions are stored in one table and a users > permission > level is stored in the user table, but both fields are integer data > types. > > HERE IS WHAT I WANT TO DO: > How do I setup a postgres constraint that will not allow an insert on > the permission table with an integer value that has more than one bit > set. In other words you could insert 1, 2, 4, 8, 16, 32, etc. because > there is only a single bit on in all of those integers, but not insert > 3, 5, 6, 7, 9, 15, 19, etc. because they have multiple??? > >
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