add null as allowed value in SQL statement

gradle.properties

@@ -1,5 +1,5 @@
 group = org.xbib
 name = database
-version = 1.4.1
+version = 1.4.2
 
 org.gradle.warning.mode = ALL

jdbc-query/src/main/java/org/xbib/jdbc/query/DatabaseImpl.java

@@ -485,8 +485,10 @@ public class DatabaseImpl implements Database {
                 sql.argLocalDate(k, (LocalDate) v);
             } else if (v instanceof LocalDateTime) {
                 sql.argLocalDateTime(k, (LocalDateTime) v);
+            } else if (v == null) {
+                sql.argNull(k);
             } else {
-                throw new DatabaseException("unknown type for param: " + (v != null ? v.getClass() : "null"));
+                throw new DatabaseException("unknown type for param: " + v.getClass());
             }
         });
     }
@@ -508,8 +510,10 @@ public class DatabaseImpl implements Database {
                 sql.argLocalDate(k, (LocalDate) v);
             } else if (v instanceof LocalDateTime) {
                 sql.argLocalDateTime(k, (LocalDateTime) v);
+            } else if (v == null) {
+                sql.argNull(k);
             } else {
-                throw new DatabaseException("unknown type for param: " + (v != null ? v.getClass() : "null"));
+                throw new DatabaseException("unknown type for param: " + v.getClass());
             }
         });
     }