优化改版

src/main/java/xyz/wbsite/wsqlite/Client.java

@@ -79,7 +79,7 @@ public class Client {
             Object arg = args[i];
 
             if (arg == null) {
-
+                ps.setNull(i + 1, Types.NULL);
             } else if (arg instanceof String) {
                 ps.setString(i + 1, (String) arg);
             } else if (arg instanceof Date) {