这样？如果有多个一样的字段名称，你要在前面把别名都带上的。不然它不知道你是哪个表的字段名称，还有排序要放在最后。。。where的后面

SELECT 

a.name,

a.month,

a.total_revenue ,

CONCAT(year, '-',IF(LENGTH(a.month) = 2, month, CONCAT('0', a.month))) as ym,

------应该要加括号吧猜测这里要改一下-----------

 concat(ifnull(round((a.total_revenue-b.total_revenue)/b.total_revenue*100,2),0),"%") as '同比' 

FROM(

SELECT name,year,month,total_revenue from `tourist_scenic_data` 

WHERE year BETWEEN left('${date1}',4) 

and left('${date2}',4),

${if(len(jq)==0,"","and name = '" +jq+ "'")}

order by month asc) a

LEFT JOIN

( SELECT name,year,month,total_revenue from `tourist_scenic_data`) b

ON b.month = a.month and b.year = a.year-1

WHERE a.ym BETWEEN '${date1}' and '${date2}

ORDER BY a.month asc