| # generate a स्वस्तिक (swastika) of arm size n | |
| # for n = 3 | |
| # * * * * * | |
| # * * | |
| # * * | |
| # * * * * * * * | |
| # * * | |
| # * * | |
| # * * * * * |
| CREATE TABLE posts | |
| ( | |
| id bigserial PRIMARY KEY, | |
| content text NOT NULL, | |
| reply_to_id bigint REFERENCES posts (id) | |
| ); | |
| TRUNCATE posts RESTART IDENTITY; -- this deletes all rows and restarts the auto-increment ID | |
| /* |
| class ArticlesService | |
| include HTTParty | |
| base_uri "https://api.example.com" | |
| read_timeout 5 # always have timeouts! | |
| # debug_output $stdout # for quick access during debugging | |
| attr_reader :auth, :headers | |
| def initialize |
For this particular problem, of modelling mutual friendship what we truly need is a "SET" data type. But Postgres doesn't really have a set datatype. However, I realised that tsvectors are sorted sets and can be used for this. So, here's a fun solution with a single row: tsvectors
Our schema:
create table friendships (
id bigint primary key,
friends tsvector
);
| CREATE TABLE rumours | |
| ( | |
| id BIGSERIAL PRIMARY KEY, | |
| description TEXT NOT NULL, | |
| created_at TIMESTAMPTZ NOT NULL DEFAULT NOW() | |
| ); | |
| CREATE TABLE tidbits | |
| ( | |
| id BIGSERIAL PRIMARY KEY, |
| #!/usr/bin/ruby | |
| # encoding: utf-8 | |
| # | |
| # Updated 2017-10-25: | |
| # - Defaults to large size (512) | |
| # - If ImageMagick is installed: | |
| # - rounds the corners (copped from @bradjasper, https://github.com/bradjasper/Download-iTunes-Icon/blob/master/itunesicon.rb) | |
| # - replace original with rounded version, converting to png if necessary | |
| # | |
| # Retrieve an iOS app icon at the highest available resolution |
| -- show running queries (pre 9.2) | |
| SELECT procpid, age(query_start, clock_timestamp()), usename, current_query | |
| FROM pg_stat_activity | |
| WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%' | |
| ORDER BY query_start desc; | |
| -- show running queries (9.2) | |
| SELECT pid, age(query_start, clock_timestamp()), usename, query | |
| FROM pg_stat_activity | |
| WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%' |
| class PostsService | |
| include HTTParty | |
| base_uri "https://api.example.com" | |
| read_timeout 5 # always have timeouts! | |
| # debug_output $stdout # for quick access during debugging | |
| attr_reader :auth, :headers | |
| def initialize(user) |
| irb(main):004:0> false&.foo | |
| NoMethodError: undefined method `foo' for false:FalseClass | |
| from (irb):4 | |
| from /Users/swanand/.rbenv/versions/2.3.1/bin/irb:11:in `<main>' | |
| irb(main):005:0> false && false.foo | |
| => false | |
| irb(main):006:0> |
| # Valid syntax | |
| def do_stuff(arg1) | |
| do_something(arg1) | |
| rescue AnError => e | |
| process_error(e) | |
| end | |
| # Syntax Error | |
| do_stuff = lambda do |arg1| | |
| do_something(arg1) |