db and ruby

sudo gem install sequel 

sqlite3 for ruby needs to be installed

sudo gem install sqlite3


require 'sequel'

Connecting

DB = Sequel.connect('sqlite://test.db') # for local database in this directory

Get Data (table)

table = DB.from(:tablename)
table.all
table.first

table.where(:column => 'value')

method chaining is allowed

table.where(:name => 'me').select(:birthday)

updating can be tricky, probably a better solution, but could not find out right now

counter = reviewer.where(:first_name => 'jxs').select(:reviews)
reviewer.where(:first_name => 'jxs').update(:reviews => counter.first.values.first.next)

mapping / selecting

reviewer.map([:gh_name]).flatten.select{|user| user unless user.nil?}

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