mybaits-plus复杂语法：count，group

rankQueryWrapper.select("count(*) as nums,file_name,open_id,rank").eq("rank",5).groupBy("file_name").orderByDesc("nums")

拼接出来的是这样的:

SELECT count(*) as nums,file_name,open_id,rank FROM rank WHERE rank = ? GROUP BY file_name ORDER BY nums DESC

！！！最需要注意的一点：

count(*)

1.不能写成count*
2.不能写成count (*)