SQL&MySQL 查询添加字段为行号

SQL：

select row_number() over(partition by name order by col desc) ,* from table;

函数“row_number”必须有使用 ORDER BY 的 OVER 子句,按照字段col来排列自动取值
partition by name order by col desc 相当于group by name order by col desc 排序过程

MySQL：

SET @r=0;
SELECT @r:=IFNULL(@r,0)+1 AS rownum,table.* FROM table ORDER BY col DESC;

与SQL不同，为循环添加字段,如果查询所有列必须加上表名table.*,若取某个字段则不需要,col1,col2...