Iteration

Good Morning:

I have a problem performing calculation.

I need to make a database with the stock of my references. These are located in two warehouses. If I use functions everything works fine but slow since it performs the calculations continuously and slows down the operation of the database.
For this reason I have thought of creating a button to make the calculation save it in numeric variables.

I have a table where all items are registered, with or without stock in one or both warehouses. This table is called 'Catálogo'.

In another table I am accumulating records with the date, the article, the warehouse and the stock, only if there is stock. This table is denoted 'Stock diario'

What I would like is for the button program to search for the last stock of each item in both warehouses and save it in a numeric field within the item tab in the 'Catálogo' table.

For this I have written the following code that does not work:
 

the reason to limit the catalog to laboratory number 1 is to limit the number of iterations and obtain information on its operation or not more quickly.

let myCat := (select 'Catálogo' where Laboratorio = 1);
let myRF := last(select 'Stock diario');
let myF := myRF.Fecha;
Fecha := myF;

for i in myCat do
let myRegCastelar := last(select 'Stock diario' where Fecha = myF and 'Almacén' = 1 and 'Catálogo' = myCat);
let myNC := cnt(myRegCastelar);
if myNC = 1 then
myCat.('Actuales Castelar' := myRegCastelar.Actuales)
else
myCat.('Actuales Castelar' := 0)
end;
let myRegCastelar := last(select 'Stock diario' where 'Catálogo'.'Nr.' = myCat and Fecha = myF and 'Almacén' = 2);
let myNC := cnt(myRegCastelar);
if myNC = 1 then
myCat.('Actuales Castelar' := myRegCastelar.Actuales)
else
myCat.('Actuales Castelar' := 0)
end;
myCat.('Actuales número' := myCat.'Actuales Castelar' + myCat.'Actuales Castellón')
end
 

Any help for iteration?