Simulating ENUM in PostgreSQL using CHECK expression

PostgreSQL is a very powerful database. One of the things that seems missing when moving from MySQL is the ability to simply create an enumeration. ENUM is nice when you have a programmatically-semantic set of values for a field.

In PostgreSQL, you have several choices. But one simple one is to create a Check expression, like follows. Skip the IS NULL part if you don’t want the field nullable.

ALTER TABLE 
   "public"."CallCenter_Transfer"
ADD CONSTRAINT 
   "CallCenter_Transfer_TransferStatus"
   CHECK (
      "TransferStatus" IS NULL 
       OR 
      "TransferStatus" = ANY(ARRAY['TransferComplete', 'TransferFailedNoAnswer', 'TransferFailedProspectLost'])
      )

git checkout -b –no-track

Ever want to checkout a new git branch from another branch without setting up tracking?

Here is the longhand way:

git checkout old-branch
git branch new-branch
git checkout new-branch

But there is a quicker way:

git checkout -b new-branch old-branch

… which does the same thing, albiet in one command.

HomeSchool Software: Review, Rendering, and Printing

After several intense programming sessions, I got the HomeSchool software in a quite suitable place for us to be able to use it to produce a log and portfolio.

I must say, it’s looking pretty nice!  It is rather amazing to look back at the year, and see in detail what was going on with Eli.

One of my favorites is on page 159 (read the letter on the telephone pole):

 

Here is a screen shot of the book view:

HomeSchool Software: Getting Close

I’ve recently been working against a deadline this month to get our Portfolio rendered, printed, and turned into the local Altoona Area School District.

The software has many improvements from the last couple days alone.  A background page renderer runs at all times, and will re-render a book’s page if anything on it changed.  The user interface for positioning images on a page is nearly complete.  I’ve enhanced the database with storage of full size JPEG images as well as info about the image (width, height, type, size).

Here is a screen shot of the page editor:

HomeSchool Software: Page Rendering (Also ImageMagick Text Example)

Last couple days have had me working on the page rendering functionality of the HomeSchool software.  I’ve made some design decisions (for now) to speed up development like fixed 8.5″ x 11″ pages.  Hopefully later I will be able to go back and improve some aspects, but for now, time is of the essence.

Here is an example page render without the photographs included.  Still need a UI for selecting photographs and positioning them on the white area of the page.

At the bottom, see an ImageMagick Text Example about the python code used to render multiple text areas and color blocks on one image…

It took me a long time to figure out how to use ImageMagick to place multiple text areas on one image.  Here are some keywords for google:

ImageMagick, ImageMagick multiple text areas, ImageMagick pdf rendering, ImageMagick text.

      PrimerFont = join(App.Path, 'Static', 'Primerb.ttf')
      PrimerFontBold = join(App.Path, 'Static', 'Primer.ttf')
      RenderFile = join(TempDir, 'Render.jpg')

      # Build the full image
      subprocess.check_call((
        '/usr/bin/convert',

        # Setup the background
        '-size', '2550x3300',
        'xc:white',

        # Title Bar
        '-fill', 'grey14', '-draw', 'rectangle 0,0 2550,300',

        # Summary bar
        '-fill', 'RoyalBlue4', '-draw', 'rectangle 0,300 2550,600',

        # Description Bar
        '-fill', 'LightGrey', '-draw', 'rectangle 0,600 2550,1050',

        # Now draw the Name
        '(',
          '-density'    , '300',
          '-fill'       , 'white',
          '-background' , 'grey14',
          '-font'       , PrimerFont,
          '-size'       , '1650x150',
          '-gravity'    , 'West',
          '-pointsize'  , '20',
          'caption:'    + self.Book.Name,
        ')',
        '-gravity', 'NorthWest', '-geometry', '+150+150', '-composite',

        # Now draw the Date
        '(',
          '-density'    , '300',
          '-fill'       , 'white',
          '-background' , 'grey14',
          '-font'       , PrimerFont,
          '-size'       , '600x150',
          '-gravity'    , 'East',
          '-pointsize'  , '20',
          'caption:' + Activity.Date.strftime('%B %d, %Y'),
        ')',
        '-gravity', 'NorthEast', '-geometry', '+150+150', '-composite',

        # Now draw the Summary
        '(',
          '-density'    , '300',
          '-fill'       , 'white',
          '-background' , 'RoyalBlue4',
          '-font'       , PrimerFontBold,
          '-size'       , '2250x300',
          '-gravity'    , 'Center',
          '-pointsize'  , '20',
          'caption:'    + Activity.Summary.replace("\n", " "),
        ')',
        '-gravity', 'North', '-geometry', '+0+300', '-composite',

        # Now draw the Description
        '(',
          '-density'    , '300',
          '-fill'       , 'black',
          '-background' , 'LightGrey',
          '-font'       , PrimerFont,
          '-size'       , '2250x450',
          '-gravity'    , 'Center',
          '-pointsize'  , '14',
          'caption:'    + Activity.Description.replace("\n", "\\n"),
        ')',
        '-gravity', 'North', '-geometry', '+0+600', '-composite',

        # Now draw the Page
        '(',
          '-density'    , '300',
          '-fill'       , 'black',
          '-background' , 'white',
          '-font'       , PrimerFont,
          '-size'       , '2250x150',  #entire right half minus 150pt margin
          '-gravity'    , 'Center',
          '-pointsize'  , '14',
          'caption:'    + 'Page {0}'.format(self.PageNumber),
        ')',
        '-gravity', 'South', '-geometry', '+0+150', '-composite',

#        NameFile, '-geometry', '+0+0', '-composite',
#        DateFile, '-geometry', '+1275+0', '-composite',
#        SummaryFile, '-geometry', '+0+150', '-composite',
#        DescriptionFile, '-geometry', '+0+450', '-composite',

        RenderFile,
        ))