MelcGraph

20 July 2018

MelcGraph is a graph algorithm library by Ciprian Teodorov. I've updated the package to handle the deprecation of #name, using 'label' in place of 'name' as inst-var and in selectors. Thanks Ciprian for giving me commit access to the repo.

Mobile-First Responsive

27 June 2018

I've finally gotten around to building a "mobile-first responsive" version of this website. Still powered by Pharo Smalltalk and Seaside, using Seaside-Bootstrap, wrapping Bootstrap 3, for the responsive HTML templating.

World Cup 2018 with Glorp

10 June 2018

I last wrote about football.db in a Jul 2014 blog post. Four years have gone by, and the World Cup is here again. This time around, I've started building a Glorp descriptor system for the World Cup data.

football.db's data is described in YAML files which are assembled into SQLite databases using tools written in Ruby. From the constructed 2014 and 2018 World Cup databases, I've created SQL dumps and placed them in the repo. To get an SQLite database from the 2018 SQL dump file:

% sqlite3 wc2018.db < wc2018.sql

In its current state, footballdb-Glorp allows querying the initial World Cup first round group membership.

| login sess |
login := Login new
  database: UDBCSQLite3Platform new;
  host: '';
  port: '';
  username: '';
  password: '';
  databaseName: '/tmp/wc2018.db';
  yourself.
sess := OFDescriptor sessionForLogin: login.
sess login.
[   Transcript clear.	
    (sess read: OFTournamentTeam) do: [ :ea |
      Transcript show: ea group title , ' - ', ea team title; cr ]
] ensure: [ sess logout ].

This Glorp descriptor may not be completed in time for this World Cup which is starting in a few days, but will be in time for the next one for sure! :-) Load it thusly:

Metacello new 
  repository: 'github://PierceNg/footballdb-Glorp:master/repo';
  baseline: 'OpenFootball';
  load.

SQLite Boolean

20 May 2018

From its documentation, SQLite does not have a separate Boolean storage class. Instead, Boolean values are stored as integers 0 (false) and 1 (true).

I've added Boolean handling to UDBC-SQLite. When writing to an SQLite database from Pharo, true is written as integer 1 and false as integer 0. SQLite uses dynamic typing, and any column in an SQLite database, except an INTEGER PRIMARY KEY column, may be used to store a value of any type, irrespective of the column's type declaration. As such, when writing Boolean values to a database, UDBC-SQLite does not check the database's type declaration.

When reading an SQLite database, UDBC-SQLite does check a column's type declaration: If a column is Boolean, UDBC-SQLite reads 1 as true, 0 as false, NULL as nil, and any other integer values raises an exception. I've encountered real world data where the string "t" means true and "f" means false for a Boolean column, so UDBC-SQLite handles these cases too.

Glorp has been similarly updated. Loading GlorpSQLite, from my development fork for now, installs both UDBC-SQLite and Glorp:

Metacello new
  repository: 'github://PierceNg/glorp-sqlite3';
  baseline: 'GlorpSQLite';
  load.

All Glorp unit tests should pass. Tested on Linux using fresh 32- and 64-bit 60540 images.