1、mysql 自动生成连续日期

  java
  @Param("countArr")String[] countArr
  sql
  select date_add(#{startTime},interval @i:=@i+1 day) as date
                   from (
                       select 1
                        <foreach item="index" collection="countArr">
                            union all select 1
                        </foreach>
                   ) as tmp,
                       (select @i:= -1) t
  例如：
 select date_add('2021-05-01',interval @i:=@i+1 day) as date
                   from (
                       select 1
                      union all select 1
                   ) as tmp,
                       (select @i:= -1) t

2、mysql 自动生成连续数字

 select  @i:=@i+1  as num
             from (
                     select 1
                    union all select 1
                    union all select 1
                    union all select 1
                    union all select 1
             ) as tmp,
                     (select @i:= 0) t