Select the 2 latest “group/batch” records from table [closed]

Answer 1

You can use Mysql's user defined variables and give a rank to rows per customer and per inventory with in a same customer group,below query will give 2 latest int_proc per inventory and same customer group if you want to get latest n number of records just change where clause to where t2.r <= n

select 
t2.id,
t2.customer_id,
t2.int_proc, 
t2.inventory
from (
select t.*,
@r:= case when @g = t.customer_id
     then
          case when @sg = t.inventory 
          then  @r+1 
          else 1 end 
      else 1 end r,
@g:= t.customer_id g,
@sg:= t.inventory sg
from test t
cross join (select @g:=null,@sg:=null,@r:=null) t1
  where t.customer_id in('A','B')
order by t.customer_id,t.inventory,t.int_proc desc
  ) t2
where t2.r <= 2
order by id

Fiddle Demo

Edit for duplicate values

If you have duplicated rows for the int_proc you have to add another sub case statement to check for repeated values and rank them accordingly

select 
t2.id,
t2.customer_id,
t2.inventory,
t2.int_proc
from (
select t.*,
@r:= case when @g = t.customer_id
     then
          case when @sg = t.inventory 
          then 
            case when @sr <> t.int_proc
            then  @r+1 
            else @r end 
          else 1 end 
      else 1 end r,
@g:= t.customer_id g,
@sg:= t.inventory sg,
@sr:= t.int_proc sr
from test t
cross join (select @g:=null,@sg:=null,@r:=null,@sr:=null) t1
  where t.customer_id in('A','B')
order by t.customer_id,t.inventory,t.int_proc desc
  ) t2
 where t2.r <= 2
order by id

Fiddle Demo 2