Squeak and MySQL

Recently I tried to use Squeak and MySQL. The Jdm classes that I pulled down from package universe got me connected just fine but there was no transaction support in the Jdm code. I wanted to begin, commit and rollback transactions. I added this behavior by doing the following.

1) I added this code to my subclass of JdmConnection in the class initialize method. This makes it so the Jdm infrastructure will allow you to execute a query that starts with these phrases (START, COMMIT, ROLLBACK).

JdmFactory40 instance queries
     at: 'START' put: #(#update);
     at: 'COMMIT' put: #(#update);
     at: 'ROLLBACK' put: #(#update);

JdmFactory41 instance queries
     at: 'START' put: #(#update);
     at: 'COMMIT' put: #(#update);
     at: 'ROLLBACK' put: #(#update);

2) I created helper methods on my JdmConnection subclass to actually do the begin, commit and rollback:

     self createStatement executeQuery: 'BEGIN'.

     self createStatement executeQuery: 'ROLLBACK'.

     self createStatement executeQuery: 'COMMIT'.

I ended up not using MySQL (not yet) because I decided to just use some cheap xml persistence until our business outgrows it.  But, I’m sure I will eventually end up using this code again.


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