create scratch.sql to store working SQL queries for #122

priv/repo/scratch.sql

@@ -0,0 +1,92 @@
+-- The purpose of this file is to have a list of working SQL Queries
+-- that we can use to inspect the data in the DB.
+-- I still find "raw" SQL to be easier to read/reason about than Ecto
+
+-- select distinct people with status.text
+SELECT DISTINCT ON (l.person_id, l.app_id)
+l.id, l.app_id, l.person_id, l.updated_at,
+st.text as status
+  FROM logs l
+  JOIN status as st on l.status_id = st.id
+
+SELECT DISTINCT ON (l.person_id, l.app_id)
+l.id, l.app_id, l.person_id, l.updated_at,
+st.text as status
+  FROM logs l
+  JOIN status as st on l.status_id = st.id
+  ORDER BY l.inserted_at
+
+-- GROUP BY
+SELECT person_id, app_id
+FROM logs
+GROUP BY person_id, app_id;
+
+-- try adding status (FAILS)
+SELECT person_id, app_id, status_id
+FROM logs
+GROUP BY (person_id, app_id);
+-- ERROR:  column "logs.status_id" must appear in the GROUP BY clause
+
+-- with the number of logs for that person:
+SELECT person_id, app_id, count(*) AS count
+FROM logs
+GROUP BY person_id, app_id;
+
+-- example from:
+-- https://stackoverflow.com/questions/9795660/distinct-on-with-order-by
+SELECT * FROM (
+  SELECT DISTINCT ON (address_id) *
+  FROM purchases 
+  WHERE product_id = 1
+  ORDER BY address_id, purchased_at DESC
+) t
+ORDER BY purchased_at DESC
+
+-- attempt to use on logs: WORKS
+SELECT * FROM (
+  SELECT DISTINCT ON (person_id) *
+  FROM logs
+  ORDER BY person_id, inserted_at DESC
+) t
+ORDER BY inserted_at DESC
+
+-- attempt JOIN in subquery:
+SELECT * FROM (
+  SELECT DISTINCT ON (person_id) *
+  FROM logs l
+  ORDER BY l.person_id, l.inserted_at DESC
+) t
+ORDER BY inserted_at DESC
+
+-- This works!!
+SELECT l.id as log_id, l.person_id, st.text as status, p."givenName", 
+l.inserted_at, p.email, l.auth_provider
+FROM (
+  SELECT DISTINCT ON (person_id) *
+  FROM logs
+  ORDER BY person_id, inserted_at DESC
+) l
+JOIN status as st on l.status_id = st.id
+JOIN people as p on l.person_id = p.id
+ORDER BY l.inserted_at DESC
+
+-- with roles (WORKS!)
+SELECT l.id as log_id, l.app_id, l.person_id, p.status, 
+st.text as status, p."givenName", p.picture,
+l.inserted_at, p.email, l.auth_provider, r.name
+FROM (
+  SELECT DISTINCT ON (person_id) *
+  FROM logs
+  ORDER BY person_id, inserted_at DESC
+) l
+JOIN people as p on l.person_id = p.id
+JOIN status as st on p.status = st.id
+JOIN people_roles as pr on p.id = pr.person_id
+JOIN roles as r on pr.role_id = r.id
+WHERE l.app_id in (1, 2)
+ORDER BY l.inserted_at DESC
+
+/* the gaps are blobs of encrypted data:
+6	1	10835816	1	verified			2020-09-24 19:28:25		github	subscriber
+4	1	1	1	verified			2020-09-24 17:28:40		google	superadmin
+*/