MySQL implementation row_number () function

Query test table by group_id group SORT_ID Top 100

SELECT id AS ‘原数据ID‘,group_id AS ‘分组ID‘,sort_id AS ‘排序条件‘,num AS ‘排名‘FROM     (SELECT  @row_number := CASE WHEN  @customer_no = group_id  THEN  @row_number + 1  ELSE  1 END   AS  num /*如果同group_id那么排名加1,否则更新为1*/    ,@customer_no := group_id  AS  group_id /*重新加载group_id*/    ,id , sort_id /*原有数据*/ FROM  test,( SELECT  @customer_no := 0,@row_number := 0)  AS  t ORDER BY group_id ,sort_id DESC ,id)a WHERE num<=100

MySQL implementation row_number () function