Most of the important database access is through the $form object.

$form->{dbh} is a non-autocommit database handle.

$form->dbinit initiates the $form->{dbh} and caches the custom fields table.

$form->callproc($procname, @arguments) returns @hashref_records
This is a wrapper for the stored procedures.  Prepares a parameterized query,
fills in the arguments, and returns the results as a list of hashrefs.