bill jobs - Page 77 - Developer IT

Complex SQL query help on aggregating values for nested subquery

- by François Beausoleil

Hi! I have people, companies, employees, events and event kinds. I'm making a report/followup sheet where people, companies and employees are the rows, and the columns are event kinds. Event kinds are simple values describing: "Promised Donation", "Received Donation", "Phoned", "Followed up" and such. Event kinds are ordered: CREATE TABLE event_kinds ( id, name, position); Events hold the actual reference to the event: CREATE TABLE events ( id, person_id, company_id, referrer_id, event_kind_id, created_at); referrer_id is another reference to people. It is the person which sent the information/tip along, and is an optional field, although I sometimes want to filter on an event_kind that has a specific referrer, while I don't for other event kinds. Notice I don't have an employee ID reference. The reference exists, but is implied. I have application code to validate that person_id and company_id really reference an employee record. The other tables are pretty basic: CREATE TABLE people ( id, name); CREATE TABLE companies ( id, name); CREATE TABLE employees ( id, person_id, company_id); I'm trying to achieve the following report: Referrer Phoned Promised Donated Francois Feb 16th Feb 20th Mar 1st Apple (Steve Jobs) Steve Ballmer Mar 3rd IBM Bill Gates Mar 7th The first row is a people record, the 2nd is an employee, and the 3rd is a company. If I asked for referrer Bill Gates for Phoned event kinds, I'd only see the 3rd row, while asking for Steve and Phoned would return no rows. Right now, I do 3 queries, one for companies, one for people and a last one for employees. I want the event kind columns to be ordered, but I do that in application code and show it properly there. Here's where I'm at so far: SELECT companies.id, companies.name, (SELECT events.id FROM events WHERE events.referrer_id = 1470 AND events.company_id = companies.id AND events.person_id IS NULL AND events.event_kind_id = 9 ORDER BY created_at DESC LIMIT 1) event_kind_9, (SELECT events.id FROM events WHERE events.company_id = companies.id AND events.person_id IS NULL AND events.event_kind_id = 10 ORDER BY created_at DESC LIMIT 1) event_kind_10, (SELECT events.created_at FROM events WHERE events.referrer_id = 1470 AND events.company_id = companies.id AND events.person_id IS NULL AND events.event_kind_id = 9 ORDER BY created_at DESC LIMIT 1) event_kind_9_order FROM "companies" SELECT people.id, people.name, (SELECT events.id FROM events WHERE events.referrer_id = 1470 AND events.company_id IS NULL AND events.person_id = people.id AND events.event_kind_id = 9 ORDER BY created_at DESC LIMIT 1) event_kind_9, (SELECT events.id FROM events WHERE events.company_id IS NULL AND events.person_id = people.id AND events.event_kind_id = 10 ORDER BY created_at DESC LIMIT 1) event_kind_10, (SELECT events.created_at FROM events WHERE events.referrer_id = 1470 AND events.company_id IS NULL AND events.person_id = people.id AND events.event_kind_id = 9 ORDER BY created_at DESC LIMIT 1) event_kind_9_order FROM "people" SELECT employees.id, employees.company_id, employees.person_id, (SELECT events.id FROM events WHERE events.referrer_id = 1470 AND events.company_id = employees.company_id AND events.person_id = employees.person_id AND events.event_kind_id = 9 ORDER BY created_at DESC LIMIT 1) event_kind_9, (SELECT events.id FROM events WHERE events.company_id = employees.company_id AND events.person_id = employees.person_id AND events.event_kind_id = 10 ORDER BY created_at DESC LIMIT 1) event_kind_10, (SELECT events.created_at FROM events WHERE events.referrer_id = 1470 AND events.company_id = employees.company_id AND events.person_id = employees.person_id AND events.event_kind_id = 9 ORDER BY created_at DESC LIMIT 1) event_kind_9_order FROM "employees" I rather suspect I'm doing this wrong. There should be an "easier" way to do it. One other filter criteria would be to filter on people/company names: WHERE LOWER(companies.name) LIKE '%apple%'. Note that I'm ordering by the dates of event_kind_9 here, and a secondary sort is by person/company name. To summarize: I want to paginate the result set, find the latest event for each cell, order the result set by the date of the latest event, and by company/person name, filter by referrer in some event kinds, but not others. For reference, I'm using PostgreSQL, from Ruby, ActiveRecord/Rails. The solution is pure SQL though.

Search Results

Search found 3134 results on 126 pages for 'bill jobs'.

Page 77/126 | < Previous Page | 73 74 75 76 77 78 79 80 81 82 83 84 | Next Page >

- by François Beausoleil

- by Aurélien Momow

- by Mike

- by Stefan

- by aleo

- by Chathura Kulasinghe

- by Jonik

- by kaibuki

- by Vecdid

- by C. Ross

- by Laplie

- by Elena

- by user248237

- by Tim Lytle

- by Algorist

- by dweebsonduty

- by Ben Lever

- by Tom Andrews

- by Johan

- by joshcomley

- by Lee

- by Badmate

- by dg

- by Walter White

- by Werner

< Previous Page | 73 74 75 76 77 78 79 80 81 82 83 84 | Next Page >