Fix SQL error when backuping course with empty thematic plan - refs #6827

main/coursecopy/classes/CourseBuilder.class.php

@@ -975,7 +975,7 @@ class CourseBuilder
                 }
             }
             //$sql = 'SELECT * FROM '.$table_thematic_plan.' WHERE c_id = '.$course_id.' AND thematic_id = '.$row['id'];
-
+            if (count($thematic_plan_id_list) > 0) {
                 $sql = "SELECT tp.*
                         FROM $table_thematic_plan tp
                             INNER JOIN $table_thematic t ON (t.id=tp.thematic_id)
@@ -989,6 +989,7 @@ class CourseBuilder
                 while ($sub_row = Database::fetch_array($result,'ASSOC')) {
                     $thematic->add_thematic_plan($sub_row);
                 }
+            }
             $this->course->add_resource($thematic);
         }
     }