code: protected String getParameterString(Collection<?> data) {
  
          StringBuffer conditions = new StringBuffer();
          conditions.append(BEGIN_CONDITION);
          Iterator<?> it = data.iterator();
          while (it.hasNext()) {
              it.next();
              conditions.append("?");
              if (it.hasNext()) {
                  conditions.append(", ");
              }
          }
          conditions.append(END_CONDITION);
          return conditions.toString();
      }
docs: Returns a SQL parameter string for the given data.<p>
  
  @param data the data
  
  @return the SQL parameter