code: protected void removeNoPrimaryKeyTable(List<TableMeta> ret) {
  		for (java.util.Iterator<TableMeta> it = ret.iterator(); it.hasNext();) {
  			TableMeta tm = it.next();
  			if (StrKit.isBlank(tm.primaryKey)) {
  				it.remove();
  				System.err.println("Skip table " + tm.name + " because there is no primary key");
  			}
  		}
  	}
docs: 移除没有主键的 table