Updating duplicates from one-to-many relationships. - postgresql

Question

This isn't your standard "how do I find duplicates" question, I know how to do find duplicates, see below. This question is how do I update said records that also have child items with matching records?
Alright, I'm going to give you whole scenario so that you can work with this problem.
Duplicate records could be inserted as a result of critical system failure.
Finding later duplicates and marking the parent commission_import_commission_junction "is_processed = True" solves this problem.
The complication is that the commission_import_commission_junction and its children commission_import_commission_junction_line_items must be identical on the columns to compare.
the tables are:
commission_import_commission_junction
- id
- created_date
- some columns that are checked for duplication
- some columns that are not checked for duplication
commission_import_commission_junction_line_items
- id
- some columns that are checked for duplication
- some columns that are not checked for duplication
(For the full table spec, check out the CREATE TABLE statements in the bottom-most block of code.)
The query to mark duplicates on just the parent table commission_import_commission_junction:
UPDATE commission_import_commission_junction cicj
SET is_processed = TRUE
FROM (
SELECT MIN(created_date) AS first_date, member_id, site_id, action_status, action_type, ad_id, commission_id, country, event_date, locking_date, order_id, original, original_action_id, posting_date, website_id, advertiser_name, commission_amount, sale_amount, aggregator_affiliate_id
FROM commission_import_commission_junction inner_imports
JOIN commission_import_commission_junction_line_items inner_items ON inner_items.commission_import_commission_junction_id = inner_imports.commission_import_commission_junction_id
GROUP BY member_id, site_id, action_status, action_type, ad_id, commission_id, country, event_date, locking_date, order_id, original, original_action_id, posting_date, website_id, advertiser_name, commission_amount, sale_amount, aggregator_affiliate_id
HAVING (COUNT(*) > 1)
) AS dups
WHERE
-- MAIN TABLE COLUMNN LIST
(cicj.member_id, cicj.site_id, cicj.action_status, cicj.action_type, cicj.ad_id, cicj.commission_id, cicj.country, cicj.event_date, cicj.locking_date, cicj.order_id, cicj.original, cicj.original_action_id, cicj.posting_date, cicj.website_id, cicj.advertiser_name, cicj.commission_amount, cicj.sale_amount, cicj.aggregator_affiliate_id)
IS NOT DISTINCT FROM
-- OTHER TABLE COLUMN LIST
(dups.member_id, dups.site_id, dups.action_status, dups.action_type, dups.ad_id, dups.commission_id, dups.country, dups.event_date, dups.locking_date, dups.order_id, dups.original, dups.original_action_id, dups.posting_date, dups.website_id, dups.advertiser_name, dups.commission_amount, dups.sale_amount, dups.aggregator_affiliate_id)
AND cicj.created_date <> dups.first_date
AND cicj.is_processed = FALSE;
Somewhere and somehow I need to check that the line_items are also duplicates.
THE CODE BELOW IS TO SETUP THE DATABASE, remember this is postgres specific.
-- "commission_import_build" is a record that keeps information about the process of collecting the commission information. Duplicate commission_import_commission_junction records will not exist with the same commission_import_build_id
-- "commission_import_commission_junction" is a record description commission information from a customers purchase.
-- "commission_import_commission_junction_line_items" are records describing items in that purchase.
DROP TABLE IF EXISTS commission_import_commission_junction_line_items;
DROP TABLE IF EXISTS commission_import_commission_junction;
DROP TABLE IF EXISTS commission_import_builds;
CREATE TABLE commission_import_builds
(
commission_import_build_id serial NOT NULL,
build_date timestamp with time zone NOT NULL,
CONSTRAINT pkey_commission_import_build_id PRIMARY KEY (commission_import_build_id),
CONSTRAINT commission_import_builds_build_date_key UNIQUE (build_date)
);
INSERT INTO commission_import_builds (commission_import_build_id, build_date) VALUES (1, '2011-01-01');
INSERT INTO commission_import_builds (commission_import_build_id, build_date) VALUES (2, '2011-01-02');
INSERT INTO commission_import_builds (commission_import_build_id, build_date) VALUES (3, '2011-01-03');
CREATE TABLE commission_import_commission_junction
(
commission_import_commission_junction_id serial NOT NULL,
member_id integer,
site_id integer,
action_status character varying NOT NULL,
action_type character varying NOT NULL,
ad_id bigint,
commission_id bigint NOT NULL,
country character varying,
event_date timestamp with time zone NOT NULL,
locking_date timestamp with time zone,
order_id character varying NOT NULL,
original boolean,
original_action_id bigint NOT NULL,
posting_date timestamp with time zone NOT NULL,
website_id bigint NOT NULL,
advertiser_name character varying,
commission_amount numeric(19,2) NOT NULL,
sale_amount numeric(19,2) NOT NULL,
aggregator_affiliate_id integer NOT NULL,
is_processed boolean NOT NULL DEFAULT false,
created_date timestamp with time zone NOT NULL DEFAULT now(),
member_transaction_id integer,
commission_import_build_id integer NOT NULL,
CONSTRAINT pkey_commission_import_commission_junction_commission_import_co PRIMARY KEY (commission_import_commission_junction_id),
CONSTRAINT fk_commission_import_commission_junction_commission_import_buil FOREIGN KEY (commission_import_build_id)
REFERENCES commission_import_builds (commission_import_build_id) MATCH SIMPLE
ON UPDATE NO ACTION ON DELETE NO ACTION
);
CREATE INDEX idx_commission_import_commission_junction_is_processed
ON commission_import_commission_junction
USING btree
(is_processed);
INSERT INTO commission_import_commission_junction (commission_import_commission_junction_id, action_status, action_type, commission_id, event_date, order_id, original_action_id, posting_date, website_id, commission_amount, sale_amount, aggregator_affiliate_id, commission_import_build_id, created_date) VALUES
(1, 'new', 'sale', 1234, '2011-02-04 14:39:52.989499-07', 'test-order', 1234567, '2011-02-04 14:39:52.989499-07', 123, 12.35, 123.45, 9876, 1, '2011-02-05');
INSERT INTO commission_import_commission_junction (commission_import_commission_junction_id, action_status, action_type, commission_id, event_date, order_id, original_action_id, posting_date, website_id, commission_amount, sale_amount, aggregator_affiliate_id, commission_import_build_id, created_date) VALUES
(2, 'new', 'sale', 1234, '2011-02-04 14:39:52.989499-07', 'test-order', 1234567, '2011-02-04 14:39:52.989499-07', 123, 12.35, 123.45, 9876, 2, '2011-02-06');
INSERT INTO commission_import_commission_junction (commission_import_commission_junction_id, action_status, action_type, commission_id, event_date, order_id, original_action_id, posting_date, website_id, commission_amount, sale_amount, aggregator_affiliate_id, commission_import_build_id, created_date) VALUES
(3, 'new', 'sale', 1234, '2011-02-04 14:39:52.989499-07', 'test-order', 1234567, '2011-02-04 14:39:52.989499-07', 123, 12.35, 123.45, 9876, 3, '2011-02-07');
SELECT * FROM commission_import_commission_junction;
CREATE TABLE commission_import_commission_junction_line_items
(
commission_import_commission_junction_line_item_id serial NOT NULL,
commission_import_commission_junction_id integer NOT NULL,
sku character varying,
quantity integer,
posting_date timestamp with time zone,
sale_amount numeric(19,2),
discount numeric(19,2),
CONSTRAINT pkey_commission_import_commission_junction_link_items_commissio PRIMARY KEY (commission_import_commission_junction_line_item_id),
CONSTRAINT fkey_commission_import_commission_junction_line_items_commissio FOREIGN KEY (commission_import_commission_junction_id)
REFERENCES commission_import_commission_junction (commission_import_commission_junction_id) MATCH SIMPLE
ON UPDATE NO ACTION ON DELETE NO ACTION
);
INSERT INTO commission_import_commission_junction_line_items (commission_import_commission_junction_id, sku, quantity, sale_amount) VALUES (1, 'test1', 3, 23.45);
INSERT INTO commission_import_commission_junction_line_items (commission_import_commission_junction_id, sku, quantity, sale_amount) VALUES (1, 'test2', 3, 67.50);
INSERT INTO commission_import_commission_junction_line_items (commission_import_commission_junction_id, sku, quantity, sale_amount) VALUES (1, 'test3', 3, 32.50);
INSERT INTO commission_import_commission_junction_line_items (commission_import_commission_junction_id, sku, quantity, sale_amount) VALUES (2, 'test1', 3, 23.45);
INSERT INTO commission_import_commission_junction_line_items (commission_import_commission_junction_id, sku, quantity, sale_amount) VALUES (2, 'test2', 3, 67.50);
INSERT INTO commission_import_commission_junction_line_items (commission_import_commission_junction_id, sku, quantity, sale_amount) VALUES (2, 'test3', 3, 32.50);
INSERT INTO commission_import_commission_junction_line_items (commission_import_commission_junction_id, sku, quantity, sale_amount) VALUES (3, 'test1', 3, 23.45);
INSERT INTO commission_import_commission_junction_line_items (commission_import_commission_junction_id, sku, quantity, sale_amount) VALUES (3, 'test2', 3, 67.50);
INSERT INTO commission_import_commission_junction_line_items (commission_import_commission_junction_id, sku, quantity, sale_amount) VALUES (3, 'test3', 3, 32.50);

Answer 1

Reminds me of duplicate elimination in direct marketing mailing lists
Regardless of the details of your tables, a parent-child dupe elimination algorithm follows these steps:
1) Get duplicates into a list that matches old key to new key (temp table)
2) Update the foreign key in the child table
3) Delete the dupes from the parent
I admire the detail in your post, but I'm going to keep it simple and easier to read with some example table/column names:
-- step 1, get the list
-- Warning: t-sql syntax, adjust for Postgres
-- if it doesn't like placement of "into..." clause
select keep.primaryKey as keepKey
, dupe.primaryKey as dupeKey
into #DupeList
from (
select min(primaryKey) as primaryKey
, dupeCriteria1
, dupeCriteria2
FROM theTable
group by dupeCriteria1,dupeCritera2
having count(*) > 1
) keep
JOIN theTable dupe
ON keep.dupeCriteria1 = dupe.dupeCriteria1
AND keep.dupeCriteria2 = dupe.dupeCriteria2
AND keep.primaryKey <> dupe.primaryKey
Once you have that, update the foreign key in the child table:
update childTable
set foreignKey = #temp1.keepKey
from #temp1
where foreignKey = #temp1.dupeKey
Then just delete everything out of the parent table:
delete from parentTable
where primaryKey in (select dupeKey from #temp1)

Answer 2

CREATE FUNCTION removeCommissionImportCommissionJunctionDuplicates() RETURNS INT AS $BODY$ DECLARE duplicate RECORD; DECLARE parent RECORD; DECLARE children commission_import_commission_junction_line_items[]; DECLARE duplicate_children commission_import_commission_junction_line_items[]; DECLARE duplicate_child_count INT; DECLARE child commission_import_commission_junction_line_items; DECLARE duplicate_child commission_import_commission_junction_line_items; DECLARE num_updates INT; BEGIN
SELECT * FROM (SELECT 0) AS value INTO num_updates;
FOR duplicate IN
SELECT cicj.*, dups.first_date
FROM commission_import_commission_junction cicj
JOIN (SELECT MIN(created_date) AS first_date, member_id, site_id, action_status, action_type, ad_id, commission_id, country, event_date, locking_date, order_id, original, original_action_id, posting_date, website_id, advertiser_name, commission_amount, sale_amount, aggregator_affiliate_id
FROM commission_import_commission_junction inner_imports
GROUP BY member_id, site_id, action_status, action_type, ad_id, commission_id, country, event_date, locking_date, order_id, original, original_action_id, posting_date, website_id, advertiser_name, commission_amount, sale_amount, aggregator_affiliate_id
HAVING (COUNT(*) > 1)) AS dups
ON (cicj.member_id, cicj.site_id, cicj.action_status, cicj.action_type, cicj.ad_id, cicj.commission_id, cicj.country, cicj.event_date, cicj.locking_date, cicj.order_id, cicj.original, cicj.original_action_id, cicj.posting_date, cicj.website_id, cicj.advertiser_name, cicj.commission_amount, cicj.sale_amount, cicj.aggregator_affiliate_id)
IS NOT DISTINCT FROM
(dups.member_id, dups.site_id, dups.action_status, dups.action_type, dups.ad_id, dups.commission_id, dups.country, dups.event_date, dups.locking_date, dups.order_id, dups.original, dups.original_action_id, dups.posting_date, dups.website_id, dups.advertiser_name, dups.commission_amount, dups.sale_amount, dups.aggregator_affiliate_id)
WHERE cicj.created_date != dups.first_date
AND cicj.is_processed = FALSE
LOOP
--RAISE NOTICE 'Looping';
-- We need to collect the parent and children of the original record.
-- Get the parent of the original
SELECT *
FROM commission_import_commission_junction cicj
WHERE (cicj.member_id, cicj.site_id, cicj.action_status, cicj.action_type, cicj.ad_id, cicj.commission_id, cicj.country, cicj.event_date, cicj.locking_date, cicj.order_id, cicj.original, cicj.original_action_id, cicj.posting_date, cicj.website_id, cicj.advertiser_name, cicj.commission_amount, cicj.sale_amount, cicj.aggregator_affiliate_id)
IS NOT DISTINCT FROM
(duplicate.member_id, duplicate.site_id, duplicate.action_status, duplicate.action_type, duplicate.ad_id, duplicate.commission_id, duplicate.country, duplicate.event_date, duplicate.locking_date, duplicate.order_id, duplicate.original, duplicate.original_action_id, duplicate.posting_date, duplicate.website_id, duplicate.advertiser_name, duplicate.commission_amount, duplicate.sale_amount, duplicate.aggregator_affiliate_id)
AND cicj.created_date = duplicate.first_date
INTO parent;
-- Get the children of the original
children := ARRAY(
SELECT cicjli
FROM commission_import_commission_junction_line_items cicjli
WHERE cicjli.commission_import_commission_junction_id
= parent.commission_import_commission_junction_id);
--RAISE NOTICE 'parent: %', parent;
--RAISE NOTICE 'children: %', children;
-- Now get the duplicates children
duplicate_children := ARRAY(
SELECT cicjli
FROM commission_import_commission_junction_line_items cicjli
WHERE cicjli.commission_import_commission_junction_id
= duplicate.commission_import_commission_junction_id);
--RAISE NOTICE 'duplicate_children: %', duplicate_children;
-- Next, compare the children of the duplicate to the children of the original parent.
-- First compare size
IF array_upper(children, 1) = array_upper(duplicate_children, 1) THEN
--RAISE NOTICE 'Same number of children in duplicate as in parent';
-- Now compare each set
SELECT * FROM (SELECT 0) AS value INTO duplicate_child_count;
FOR child_index IN array_lower(children, 1) .. array_upper(children, 1) LOOP
child := children[child_index];
FOR duplicate_child_index IN array_lower(duplicate_children, 1) .. array_upper(duplicate_children, 1) LOOP
duplicate_child := duplicate_children[duplicate_child_index];
IF (child.sku, child.quantity, child.posting_date, child.sale_amount, child.discount) IS NOT DISTINCT FROM (duplicate_child.sku, duplicate_child.quantity, duplicate_child.posting_date, duplicate_child.sale_amount, duplicate_child.discount) THEN
SELECT * FROM (SELECT duplicate_child_count + 1) AS value INTO duplicate_child_count;
EXIT;
END IF;
END LOOP;
END LOOP;
--RAISE NOTICE 'Duplicate Child Count: %', duplicate_child_count;
-- If we have the same number of duplicates as there are records
IF duplicate_child_count = array_upper(duplicate_children, 1) THEN
-- Update the duplicate record as processed.
--RAISE NOTICE 'Marking duplicate % as is_processed', duplicate;
UPDATE commission_import_commission_junction cicj SET is_processed = TRUE WHERE cicj.commission_import_commission_junction_id
= duplicate.commission_import_commission_junction_id;
SELECT * FROM (SELECT num_updates + 1) AS value INTO num_updates;
END IF;
END IF;
END LOOP;
--RAISE NOTICE 'Updates: %', num_updates;
RETURN num_updates; END; $BODY$ LANGUAGE plpgsql;