1 files changed, 12 insertions, 2 deletions
diff --git a/lib/field.cpp b/lib/field.cpp
index d7adbb3..168935c 100644
--- a/lib/field.cpp
+++ b/lib/field.cpp

@@ -70,12 +70,22 @@ namespace verbly {
  
  field::operator filter() const
  {
-    return filter(*this, filter::comparison::is_not_null);
+    if (isJoin())
+    {
+      return filter(*this, filter::comparison::matches, filter());
+    } else {
+      return filter(*this, filter::comparison::is_not_null);
+    }
  }
  
  filter field::operator!() const
  {
-    return filter(*this, filter::comparison::is_null);
+    if (isJoin())
+    {
+      return filter(*this, filter::comparison::does_not_match, filter());
+    } else {
+      return filter(*this, filter::comparison::is_null);
+    }
  }
  
  filter field::operator%=(filter joinCondition) const