minor: check business rules before making changes in the DB to avoid unnecessary work

SVN: 16542

openbis/source/java/ch/systemsx/cisd/openbis/generic/server/business/bo/SampleTable.java

@@ -306,8 +306,8 @@ public final class SampleTable extends AbstractSampleBusinessObject implements I
 
         try
         {
-            getSampleDAO().createSamples(samples);
             checkBusinessRules();
+            getSampleDAO().createSamples(samples);
         } catch (final DataAccessException ex)
         {
             throwException(ex, String.format("One of samples"));