SimpleTesting-PDOException: SQLSTATE[42S02] I am in the processes of developing a module. I am trying to incorporate SimpleTest module in order to have a separate place that contains my code tests.

However, when I try to run a query against the tables in the database, which are build by me, I get:
PDOException: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'playground.simpletest311135TABLENAME
It tries to find a table simpletest311135TABLENAME while it should look for TABLENAME.
It always adds simpletest and some random number.

When I run queries against drupal default tables, like users and sessions, everything works perfect.
Any workaround?

Giannis
This behavior is correct. SimpleTest sets up a new site environment for every test case, using a table name prefix.

You probably forgot to install your module by overriding the setUp() method. Once your module is installed the query should work.