This is an experimental build of a simple "twitter" application in Postgres. The goal is to push as much logic into the database as possible. This includes contraints, validations, functions, and triggers!
- I'm using the dbext VIM plugin for splitscreen SQL and executed results.
- I use the binding
<leader>seeto execute all statements in the buffer. (Sql Execute Everything)
The compile executable combines all files under sql/ into compiled.sql or development.sql.
bin/
compile
sql/
000_development.sql
001_schemas.sql
002_extensions.sql
003_functions.sql
004_trigger_functions.sql
005_behaviors.sql
006_tables.sql
007_views.sql
008_constraints.sql
009_indexes.sql
010_triggers.sql
999_development.sql
test/
- seed database from twitter stream
- favorites
- followers
- mentions
- replies
- retweets
- tags
- tweets
- users
INSERT INTO users (username) VALUES
('bob'),
('doug'),
('jane'),
('steve'),
('tom');
INSERT INTO tweets (post, user_id) VALUES
('My first tweet!', random_user_id()),
('Another tweet with a tag! #hello-world @missing', random_user_id()),
('My second tweet! #hello-world #hello-world-again', random_user_id()),
('Is anyone else hungry? #imHUNGRY #gimmefood @TOM @jane', random_user_id()),
('@steve hola!', random_user_id()),
('@bob I am! #imhungry #metoo #gimmefood #now', random_user_id());
INSERT INTO favorites (user_id, tweet_id)
SELECT id as user_id, random_tweet_id() as tweet_id
FROM users;
INSERT INTO followers (follower_id, user_id)
SELECT id as follower_id, random_user_id(id) as user_id
FROM users;
INSERT INTO replies (tweet_id, reply_id)
SELECT id as tweet_id, random_tweet_id(id) as reply_id
FROM tweets
LIMIT 2;
INSERT INTO retweets (tweet_id, retweet_id)
SELECT id as tweet_id, random_tweet_id(id) as retweet_id
FROM tweets
LIMIT 2;
SELECT id, username, followers, following, favorites, mentions, tweets FROM users;
SELECT * FROM mentions;
-------------------------------------------------------------------------------
SELECT username, tweets.favorites, replies, retweets, tweets.mentions, tags
FROM tweets JOIN users on tweets.user_id = users.id;
DELETE FROM tweets
WHERE id IN (
SELECT t.id
FROM tweets t
ORDER BY random()
LIMIT 1
);
UPDATE tweets
SET post = 'replaced!'
WHERE id IN (
SELECT t.id
FROM tweets t
ORDER BY random()
LIMIT 1
);
SELECT username, tweets.favorites, replies, retweets, tweets.mentions, tags
FROM tweets JOIN users on tweets.user_id = users.id;
-------------------------------------------------------------------------------
SELECT * FROM taggings;
SELECT id, name, tweets FROM tags;
Connection: T(PGSQL) D(twitter) U(shuber) at 12:52
id | username | followers | following | favorites | mentions | tweets
--------------------------------------+----------+-----------+-----------+-----------+----------+--------
267ce9ac-c3df-4bf4-bbed-3aee28094a52 | doug | 2 | 1 | 1 | 0 | 1
46c226b4-f26f-412c-a72f-9fe1b35da997 | bob | 0 | 1 | 1 | 1 | 1
9d2860c9-a713-43e5-a384-c1b24b3d1c4d | tom | 2 | 1 | 1 | 1 | 1
da1b62ea-c0bc-4f29-9d27-212144bc29c0 | jane | 0 | 1 | 1 | 1 | 3
7bba5bea-d98b-4079-abea-fed05034dc6a | steve | 1 | 1 | 1 | 1 | 0
(5 rows)
user_id | tweet_id
--------------------------------------+--------------------------------------
da1b62ea-c0bc-4f29-9d27-212144bc29c0 | 2d872de0-46cc-44aa-9aec-015fd5291c72
9d2860c9-a713-43e5-a384-c1b24b3d1c4d | 2d872de0-46cc-44aa-9aec-015fd5291c72
7bba5bea-d98b-4079-abea-fed05034dc6a | 1bab8cad-9cac-473d-a689-fbc710aaaea6
46c226b4-f26f-412c-a72f-9fe1b35da997 | 3bc21b9d-c778-4c64-84b8-798fd65072d8
(4 rows)
username | favorites | replies | retweets | mentions | tags
----------+-----------+---------+----------+------------+---------------------------------
tom | 1 | 0 | 0 | {} | {hello-world,hello-world-again}
jane | 2 | 0 | 0 | {bob} | {gimmefood,imhungry,metoo,now}
doug | 0 | 1 | 0 | {} | {}
jane | 0 | 1 | 0 | {steve} | {}
jane | 1 | 0 | 1 | {jane,tom} | {gimmefood,imhungry}
bob | 1 | 0 | 1 | {missing} | {hello-world}
(6 rows)
username | favorites | replies | retweets | mentions | tags
----------+-----------+---------+----------+------------+---------------------------------
tom | 1 | 0 | 0 | {} | {hello-world,hello-world-again}
doug | 0 | 1 | 0 | {} | {}
jane | 1 | 0 | 1 | {jane,tom} | {gimmefood,imhungry}
bob | 1 | 0 | 1 | {missing} | {hello-world}
jane | 2 | 0 | 0 | {} | {}
(5 rows)
tag_id | tweet_id
--------------------------------------+--------------------------------------
579e5a0f-5835-46ac-aced-528f8cd6e913 | 1d572544-8a84-4053-aef5-238260be3fa3
579e5a0f-5835-46ac-aced-528f8cd6e913 | 37421d41-416e-463d-9ad5-b9570f9356e8
0d86a554-0db2-4f60-8833-3d6bd6ed58af | 37421d41-416e-463d-9ad5-b9570f9356e8
c2620f3c-5a5c-4fa5-88f4-f01e2e12173e | 2d872de0-46cc-44aa-9aec-015fd5291c72
3efbea1c-3002-4b87-917b-d3ead6483983 | 2d872de0-46cc-44aa-9aec-015fd5291c72
(5 rows)
id | name | tweets
--------------------------------------+-------------------+--------
579e5a0f-5835-46ac-aced-528f8cd6e913 | hello-world | 2
0d86a554-0db2-4f60-8833-3d6bd6ed58af | hello-world-again | 1
c2620f3c-5a5c-4fa5-88f4-f01e2e12173e | gimmefood | 1
3efbea1c-3002-4b87-917b-d3ead6483983 | imhungry | 1
(4 rows)
This is mostly for development. This object contains methods to return a random record from various tables. Also add _id suffixed versions of the methods to return a random record's primary key.
random.tag()random.tweet()random.user()
Public API for interacting with tweets
tweets.createtweets.deletetweets.findtweets.for_usertweets.update
Public API for interacting with tags
tags.find_or_create(name text)tags.listen(names text[])tags.tweets(names text[])
Or maybe put everything under the api schema
api.create_reply(tweet_id uuid, post text, user_id uuid)api.create_retweet(tweet_id uuid, post text, user_id uuid)api.create_tweet(post text, user_id uuid)api.delete_tweet(tweet_id uuid)api.favorite_tweet(tweet_id uuid, user_id uuid)api.unfavorite_tweet(tweet_id uuid, user_id uuid)api.follow_user(user_id uuid, follower_id uuid)api.unfollow_user(user_id uuid, follower_id uuid)