How to query group in mysql

Question

i have two table

tblstock

id	name	stock
1	aa	20
2	ab	25
3	ac	30

tblinputs

id	name	lot	qty
1	aa	1.01	5
2	aa	1.02	5
3	aa	2.03	10
4	ab	3.04	15
5	ab	2.03	10
6	ac	1.01	10
7	ac	1.04	10
8	ac	2.01	10

how to implement query join and group by on below result

id	name	lot1	lot 2	lot 3	lot 4	stock
1	aa	1.01	1.02	2.03	0	20
2	ab	3.04	2.03	0	0	25
3	ac	1.01	2.01	1.04	0	30

i has try, but not succes

SELECT name, lot FROM tblinputs INNER JOIN tblitems ON tblitems.id=tblinputs.name GROUP BY lot

Answer 1

I you can live without the lot1-lot4 headers a group_concat is the simplest way to go

SELECT ts.id,ts.name,group_concat(ti.lot order by ti.id) lots,max(ts.stock) qty
from tblstock ts
join tblinputs ti on ti.name = ts.name
group by ts.id,ts.name;

if you do need the headers then assign a row_number and conditionally aggregate

with cte as(
SELECT ts.id,ts.name,row_number() over(partition  by ts.id order by ti.id) rn,
        ti.lot
from tblstock ts
join tblinputs ti on ti.name = ts.name
),
cte1 as
(select cte.id,cte.name,
        max(case when rn = 1 then cte.lot else 0 end) lot1,
        max(case when rn = 2 then cte.lot else 0 end) lot2,
        max(case when rn = 3 then cte.lot else 0 end) lot3,
        max(case when rn = 4 then cte.lot else 0 end) lot4
from cte
group by cte.id,cte.name
)
select cte1.* , ts.stock
from cte1
join tblstock ts on ts.id = cte1.id;

if there can be an unknown, possibly infinite number of lots per id then you need to go dynamic sql

https://dbfiddle.uk/mceDn-Zk