EMPIREDB-340
dont use command param when value is null
diff --git a/empire-db/src/main/java/org/apache/empire/db/DBCommand.java b/empire-db/src/main/java/org/apache/empire/db/DBCommand.java
index b8b8b6f..67b1f6d 100644
--- a/empire-db/src/main/java/org/apache/empire/db/DBCommand.java
+++ b/empire-db/src/main/java/org/apache/empire/db/DBCommand.java
@@ -359,7 +359,7 @@
     protected boolean useCmdParam(DBColumn col, Object value)
     {
         // Cannot wrap DBExpr or DBSystemDate
-        if (value instanceof DBExpr || value instanceof DBDatabase.DBSystemDate)
+        if (value==null || value instanceof DBExpr || value instanceof DBDatabase.DBSystemDate)
             return false;
         // Check if prepared statements are enabled
         if (isPreparedStatementsEnabled())