Merge pull request 'Fix: Multiple //copy Schematics' (#38) from nodemember into master

Reviewed-on: #38
Reviewed-by: Lixfel <lixfel@steamwar.de>

src/de/steamwar/sql/SchematicNode.java

@@ -48,7 +48,7 @@ public class SchematicNode {
     private static final Statement delete = table.delete(Table.PRIMARY);
 
     private static final SelectStatement<SchematicNode> byId = new SelectStatement<>(table, nodeSelector + "WHERE NodeId = ?");
-    private static final SelectStatement<SchematicNode> byOwnerNameParent = new SelectStatement<>(table, nodeSelector + "WHERE NodeOwner = ? AND NodeName = ? AND ParentNode = ?");
+    private static final SelectStatement<SchematicNode> byOwnerNameParent = new SelectStatement<>(table, nodeSelector + "WHERE NodeOwner = ? AND NodeName = ? AND ParentNode " + Statement.NULL_SAFE_EQUALS + "?");
     private static final SelectStatement<SchematicNode> byParent = new SelectStatement<>(table, nodeSelector + "WHERE ParentNode" + Statement.NULL_SAFE_EQUALS + "? ORDER BY NodeName");
     private static final SelectStatement<SchematicNode> dirsByParent = new SelectStatement<>(table, nodeSelector + "WHERE ParentNode" + Statement.NULL_SAFE_EQUALS + "? AND NodeType is NULL ORDER BY NodeName");
     private static final SelectStatement<SchematicNode> byOwnerType = new SelectStatement<>(table, nodeSelector + "WHERE NodeOwner = ? AND NodeType = ? ORDER BY NodeName");