Bitwise menu problem

• corunjohnson

  SSC Rookie

  Points: 43

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  July 7, 2008 at 5:53 am

  #193517

  Hi,

  I am currently building a website menu system which is stored in SQL Server and which will be permission driven.

  In the frontend I have 3 enumerated roles.

  Reader = 1

  Admin = 2

  Developer = 4

  A user can be any combination of the above. Next to each menu item I store the required permission level. So a menu item with a permission level of 7 should be able to be seen by roles: Reader, Admin and Developer, whereas a menu permission of 6 should only be seen by anyone assigned to roles: Admin or Developer.

  I have tried the following syntax but this does not work.

  SELECT MenuItem, URL

  FROMMenu

  WHERE ((@permission & Permission) = @permission)

  Using this approach if @permission = 3 (Reader and Admin) it doesn't pick up where Permission = 6 (which it should because Admin is in 6).

  Hope this makes sense. Any help would be gratefully received.

  Thanks

  Corun

• Andras Belokosztolszki

  SSC-Insane

  Points: 22031

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  July 7, 2008 at 6:28 am

  #838789

  Since you are not requiring that all permission bits should be present when comparing, but only one permission bit is set, you could use:

  SELECT MenuItem, URL

  FROM Menu

  WHERE ((@permission & Permission) > 0)

  Regards,

  Andras

  ---

  Andras Belokosztolszki, MCPD, PhD
  GoldenGate Software

• corunjohnson

  SSC Rookie

  Points: 43

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  July 7, 2008 at 6:32 am

  #838793

  Thanks that's exactly what I was looking for 🙂