${if(len(大类) == 0,"","and big_type = '" + 大类 + "'")}
${if(len(大类) == 0,"","and big_type in('" + 大类 + "')")}
然后,分割符手动输入','
${if(len(大类) == 0,"","and big_type in ('" + 大类 + "')")}