Submitted By: bubble76
A build-in function to handle ACL-subtype in Blob fields:
SELECT * FROM mytable WHERE RDB$CHECKACL('myaclfield', 'R')
to show all rows, the current user or the current role
is allowed to read.
UPDATE mytable SET myaclfield = RDB$SETACL(myaclfield,
to add read-permission to current user and deny
write-permissen to current role.