-- -- /packages/acs-kernel/sql/rel-constraints-create.sql -- -- Add support for relational constraints based on relational segmentation. -- -- @author Oumi Mehrotra (oumi@arsdigita.com) -- @creation-date 2000-11-22 -- @cvs-id $Id: rel-constraints-create.sql,v 1.1 2002/07/09 17:34:58 rmello Exp $ -- Copyright (C) 1999-2000 ArsDigita Corporation -- This is free software distributed under the terms of the GNU Public -- License. Full text of the license is available from the GNU Project: -- http://www.fsf.org/copyleft/gpl.html -- WARNING! -- Relational constraints is a new and experimental concept. The API may -- change in the future, particularly the functions marked "EXPERIMENTAL". -- begin acs_object_type.create_type( object_type => 'rel_constraint', pretty_name => 'Relational Constraint', pretty_plural => 'Relational Constraints', supertype => 'acs_object', table_name => 'rel_constraints', id_column => 'constraint_id', package_name => 'rel_constraint' ); end; / show errors create table rel_constraints ( constraint_id integer constraint rel_constraints_pk primary key constraint rc_constraint_id_fk references acs_objects(object_id), constraint_name varchar(100) not null, rel_segment not null constraint rc_rel_segment_fk references rel_segments (segment_id), rel_side char(3) default 'two' not null constraint rc_rel_side_ck check (rel_side in ('one', 'two')), required_rel_segment not null constraint rc_required_rel_segment references rel_segments (segment_id), constraint rel_constraints_uq unique (rel_segment, rel_side, required_rel_segment) ); -- required_rel_segment has a foreign key reference - create an index create index rel_constraint_req_rel_seg_idx on rel_constraints(required_rel_segment); comment on table rel_constraints is ' Defines relational constraints. The relational constraints system is intended to support applications in modelling and applying constraint rules on inter-party relatinships based on relational party segmentation. '; comment on column rel_constraints.constraint_name is ' The user-defined name of this constraint. '; comment on column rel_constraints.rel_segment is ' The segment for which the constraint is defined. '; comment on column rel_constraints.rel_side is ' The side of the relation the constraint applies to. '; comment on column rel_constraints.required_rel_segment is ' The segment in which elements must be in to satisfy the constraint. '; ----------- -- VIEWS -- ----------- -- View rel_constraints_violated_one -- -- pseudo sql: -- -- select all the side 'one' constraints -- from the constraints and the associated relations of rel_segment -- where the relation's container_id (i.e., object_id_one) is not in the -- relational segment required_rel_segment. create or replace view rel_constraints_violated_one as select constrained_rels.* from (select rel_constraints.constraint_id, rel_constraints.constraint_name, r.rel_id, r.container_id, r.party_id, r.rel_type, rel_constraints.rel_segment, rel_constraints.rel_side, rel_constraints.required_rel_segment from rel_constraints, rel_segment_party_map r where rel_constraints.rel_side = 'one' and rel_constraints.rel_segment = r.segment_id ) constrained_rels, rel_segment_party_map rspm where rspm.segment_id(+) = constrained_rels.required_rel_segment and rspm.party_id(+) = constrained_rels.container_id and rspm.party_id is null; -- View rel_constraints_violated_two -- -- pseudo sql: -- -- select all the side 'two' constraints -- from the constraints and the associated relations of rel_segment -- where the relation's party_id (i.e., object_id_two) is not in the -- relational segment required_rel_segment. create or replace view rel_constraints_violated_two as select constrained_rels.* from (select rel_constraints.constraint_id, rel_constraints.constraint_name, r.rel_id, r.container_id, r.party_id, r.rel_type, rel_constraints.rel_segment, rel_constraints.rel_side, rel_constraints.required_rel_segment from rel_constraints, rel_segment_party_map r where rel_constraints.rel_side = 'two' and rel_constraints.rel_segment = r.segment_id ) constrained_rels, rel_segment_party_map rspm where rspm.segment_id(+) = constrained_rels.required_rel_segment and rspm.party_id(+) = constrained_rels.party_id and rspm.party_id is null; -- View: rc_all_constraints -- -- Question: Given group :group_id and rel_type :rel_type . . . -- -- What segments must a party be in -- if the party were to be on side :rel_side of a relation of -- type :rel_type to group :group_id ? -- -- Answer: select required_rel_segment -- from rc_all_constraints -- where group_id = :group_id -- and rel_type = :rel_type -- and rel_side = :rel_side -- -- Notes: we take special care not to get identity rows, where group_id and -- rel_type are equivalent to segment_id. This can happen if there are some -- funky constraints in the system, such as membership to Arsdigita requires -- user_profile to Arsdigita. Then you could get rows from the -- rc_all_constraints view saying that: -- user_profile to Arsdigita -- requires being in the segment of Arsdigita Users. -- -- This happens because user_profile is a type of memebrship, and there's a -- constraint saying that membership to Arsdigita requires being in the -- Arsdigita Users segment. We eliminate such rows from the rc_all_constraints -- view with the "not (...)" clause below. -- create or replace view rc_all_constraints as select group_rel_types.group_id, group_rel_types.rel_type, rel_constraints.rel_segment, rel_constraints.rel_side, required_rel_segment from rel_constraints, rel_segment_group_rel_type_map group_rel_types, rel_segments req_seg where rel_constraints.rel_segment = group_rel_types.segment_id and rel_constraints.required_rel_segment = req_seg.segment_id and not (req_seg.group_id = group_rel_types.group_id and req_seg.rel_type = group_rel_types.rel_type); create or replace view rc_all_distinct_constraints as select distinct group_id, rel_type, rel_segment, rel_side, required_rel_segment from rc_all_constraints; -- THIS VIEW IS FOR COMPATIBILITY WITH EXISTING CODE -- New code should use rc_all_constraints instead! -- -- View: rc_required_rel_segments -- -- Question: Given group :group_id and rel_type :rel_type . . . -- -- What segments must a party be in -- if the party were to be belong to group :group_id -- through a relation of type :rel_type ? -- -- Answer: select required_rel_segment -- from rc_required_rel_segments -- where group_id = :group_id -- and rel_type = :rel_type -- create or replace view rc_required_rel_segments as select distinct group_id, rel_type, required_rel_segment from rc_all_constraints where rel_side = 'two'; -- View: rc_parties_in_required_segs -- -- Question: Given group :group_id and rel_type :rel_type . . . -- -- What parties are "allowed" to be in group :group_id -- through a relation of type :rel_type ? By "allowed", -- we mean that no relational constraints would be violated. -- -- Answer: select party_id, acs_object.name(party_id) -- from parties_in_rc_required_rel_segments -- where group_id = :group_id -- and rel_type = :rel_type -- create or replace view rc_parties_in_required_segs as select parties_in_required_segs.group_id, parties_in_required_segs.rel_type, parties_in_required_segs.party_id from (select required_segs.group_id, required_segs.rel_type, seg_parties.party_id, count(*) as num_matching_segs from rc_required_rel_segments required_segs, rel_segment_party_map seg_parties where required_segs.required_rel_segment = seg_parties.segment_id group by required_segs.group_id, required_segs.rel_type, seg_parties.party_id) parties_in_required_segs, (select group_id, rel_type, count(*) as total from rc_required_rel_segments group by group_id, rel_type) total_num_required_segs where parties_in_required_segs.group_id = total_num_required_segs.group_id and parties_in_required_segs.rel_type = total_num_required_segs.rel_type and parties_in_required_segs.num_matching_segs = total_num_required_segs.total UNION ALL select group_rel_type_combos.group_id, group_rel_type_combos.rel_type, parties.party_id from rc_required_rel_segments, (select groups.group_id, comp_or_member_rel_types.rel_type from groups, (select object_type as rel_type from acs_object_types start with object_type = 'membership_rel' or object_type = 'composition_rel' connect by supertype = prior object_type) comp_or_member_rel_types ) group_rel_type_combos, parties where rc_required_rel_segments.group_id(+) = group_rel_type_combos.group_id and rc_required_rel_segments.rel_type(+) = group_rel_type_combos.rel_type and rc_required_rel_segments.group_id is null; -- View: rc_valid_rel_types -- -- Question: What types of membership or composition are "valid" -- for group :group_id ? A membership or composition -- type R is "valid" when no relational constraints would -- be violated if a party were to belong to group :group_id -- through a rel of type R. -- -- Answer: select rel_type -- from rc_valid_rel_types -- where group_id = :group_id -- -- create or replace view rc_valid_rel_types as select side_one_constraints.group_id, side_one_constraints.rel_type from (select required_segs.group_id, required_segs.rel_type, count(*) as num_satisfied from rc_all_constraints required_segs, rel_segment_party_map map where required_segs.rel_side = 'one' and required_segs.required_rel_segment = map.segment_id and required_segs.group_id = map.party_id group by required_segs.group_id, required_segs.rel_type) side_one_constraints, (select group_id, rel_type, count(*) as total from rc_all_constraints where rel_side = 'one' group by group_id, rel_type) total_side_one_constraints where side_one_constraints.group_id = total_side_one_constraints.group_id and side_one_constraints.rel_type = total_side_one_constraints.rel_type and side_one_constraints.num_satisfied = total_side_one_constraints.total UNION ALL select group_rel_type_combos.group_id, group_rel_type_combos.rel_type from (select * from rc_all_constraints where rel_side='one') rc_all_constraints, (select groups.group_id, comp_or_member_rel_types.rel_type from groups, (select object_type as rel_type from acs_object_types start with object_type = 'membership_rel' or object_type = 'composition_rel' connect by supertype = prior object_type) comp_or_member_rel_types ) group_rel_type_combos where rc_all_constraints.group_id(+) = group_rel_type_combos.group_id and rc_all_constraints.rel_type(+) = group_rel_type_combos.rel_type and rc_all_constraints.group_id is null; -- View: rc_violations_by_removing_rel -- -- Question: Given relation :rel_id -- -- If we were to remove the relation specified by rel_id, -- what constraints would be violated and by what parties? -- -- Answer: select r.rel_id, r.constraint_id, r.constraint_name -- acs_object_type.pretty_name(r.rel_type) as rel_type_pretty_name, -- acs_object.name(r.object_id_one) as object_id_one_name, -- acs_object.name(r.object_id_two) as object_id_two_name -- from rc_violations_by_removing_rel r -- where r.rel_id = :rel_id -- create or replace view rc_violations_by_removing_rel as select r.rel_type as viol_rel_type, r.rel_id as viol_rel_id, r.object_id_one as viol_object_id_one, r.object_id_two as viol_object_id_two, s.rel_id, cons.constraint_id, cons.constraint_name, map.segment_id, map.party_id, map.group_id, map.container_id, map.ancestor_rel_type from acs_rels r, rel_segment_party_map map, rel_constraints cons, (select s.segment_id, r.rel_id, r.object_id_two from rel_segments s, acs_rels r where r.object_id_one = s.group_id and r.rel_type = s.rel_type) s where map.party_id = r.object_id_two and map.rel_id = r.rel_id and r.object_id_two = s.object_id_two and cons.rel_segment = map.segment_id and cons.required_rel_segment = s.segment_id; -- View: rc_segment_required_seg_map -- -- Question: Given a relational segment :rel_segment . . . -- -- What are all the segments in the system that a party has to -- be in if the party were to be on side :rel_side of a relation -- in segement :rel_segment? -- -- We want not only the direct required_segments (which we could -- get from the rel_constraints table directly), but also the -- indirect ones (i.e., the segments that are required by the -- required segments, and so on). -- -- Answer: select required_rel_segment -- from rc_segment_required_seg_map -- where rel_segment = :rel_segment -- and rel_side = :rel_side -- -- create or replace view rc_segment_required_seg_map as select rc.rel_segment, rc.rel_side, rc_required.required_rel_segment from rel_constraints rc, rel_constraints rc_required where rc.rel_segment in ( select rel_segment from rel_constraints start with rel_segment = rc_required.rel_segment connect by required_rel_segment = prior rel_segment and prior rel_side = 'two' ); -- View: rc_segment_dependency_levels -- -- This view is designed to determine what order of segments is safe -- to use when adding a party to multiple segments. -- -- Question: Given a table or view called segments_I_want_to_be_in, -- which segments can I add a party to first, without violating -- any relational constraints? -- -- Answer: select segment_id -- from segments_I_want_to_be_in s, -- rc_segment_dependency_levels dl -- where s.segment_id = dl.segment_id(+) -- order by nvl(dl.dependency_level, 0) -- -- Note: dependency_level = 1 is the minimum dependency level. -- dependency_level = N means that you cannot add a party to the -- segment until you first add the party to some -- segment of dependency_level N-1 (this view doesn't -- tell you which segment -- you can get that info -- from rel_constraints table or other views. -- -- Another Note: not all segemnts in rel_segemnts are returned by this view. -- This view only returns segments S that have at least one rel_constraints row -- where rel_segment = S. Segments that have no constraints defined on them -- can be said to have dependency_level=0, hence the outer join and nvl in the -- example query above (see "Answer:"). I could have embeded that logic into -- this view, but that would unnecessarily degrade performance. -- create or replace view rc_segment_dependency_levels as select rel_segment as segment_id, max(tree_level) as dependency_level from (select rel_segment, level as tree_level from rel_constraints connect by required_rel_segment = prior rel_segment and prior rel_side = 'two') group by rel_segment ; -------------- -- PACKAGES -- -------------- create or replace package rel_constraint as function new ( --/** Creates a new relational constraint -- -- @author Oumi Mehrotra (oumi@arsdigita.com) -- @creation-date 12/2000 -- --*/ constraint_id in rel_constraints.constraint_id%TYPE default null, constraint_type in acs_objects.object_type%TYPE default 'rel_constraint', constraint_name in rel_constraints.constraint_name%TYPE, rel_segment in rel_constraints.rel_segment%TYPE, rel_side in rel_constraints.rel_side%TYPE default 'two', required_rel_segment in rel_constraints.required_rel_segment%TYPE, context_id in acs_objects.context_id%TYPE default null, creation_user in acs_objects.creation_user%TYPE default null, creation_ip in acs_objects.creation_ip%TYPE default null ) return rel_constraints.constraint_id%TYPE; procedure delete ( constraint_id in rel_constraints.constraint_id%TYPE ); function get_constraint_id ( --/** Returns the constraint_id associated with the specified -- rel_segment and required_rel_segment for the specified site. -- -- @author Oumi Mehrotra (oumi@arsdigita.com) -- @creation-date 12/2000 -- --*/ rel_segment in rel_constraints.rel_segment%TYPE, rel_side in rel_constraints.rel_side%TYPE default 'two', required_rel_segment in rel_constraints.required_rel_segment%TYPE ) return rel_constraints.constraint_id%TYPE; function violation ( --/** Checks to see if there a relational constraint is violated -- by the precense of the specified relation. If not, returns -- null. If so, returns an appropriate error string. -- -- @author Oumi Mehrotra (oumi@arsdigita.com) -- @creation-date 12/2000 -- -- @param rel_id The relation for which we want to find -- any violations --*/ rel_id in acs_rels.rel_id%TYPE ) return varchar; function violation_if_removed ( --/** Checks to see if removing the specified relation would violate -- a relational constraint. If not, returns null. If so, returns -- an appropriate error string. -- -- @author Michael Bryzek (mbryzek@arsdigita.com) -- @creation-date 1/2001 -- -- @param rel_id The relation that we are planning to remove --*/ rel_id in acs_rels.rel_id%TYPE ) return varchar; end; / show errors