Skill Performance

// ✅ Correct: SetRange first, SetLoadFields before Find
Item.SetRange("Third Party Item Exists", false);
Item.SetLoadFields("Item Category Code", Description);
if Item.FindSet() then
    repeat
        // Only "Item Category Code" and Description loaded from DB
    until Item.Next() = 0;

// ❌ Wrong: SetLoadFields after SetRange (ignored), loads all fields
Item.SetLoadFields("Item Category Code");
Item.SetRange("Third Party Item Exists", false);
Item.FindFirst();

// ❌ Wrong: No filter — full table scan
procedure GetCustomersByCity(CityFilter: Text): Integer
var
    Customer: Record Customer;
    Count: Integer;
begin
    if Customer.FindSet() then       // loads entire Customer table
        repeat
            if Customer.City = CityFilter then
                Count += 1;
        until Customer.Next() = 0;
end;

// ✅ Correct: Filter pushed to DB
procedure GetCustomersByCity(CityFilter: Text): Integer
var
    Customer: Record Customer;
begin
    Customer.SetRange(City, CityFilter);
    Customer.SetRange(Blocked, Customer.Blocked::" ");
    exit(Customer.Count());
end;

// ❌ Loop accumulation — N rows fetched and processed in AL
procedure GetTotalSales(CustomerNo: Code[20]): Decimal
var
    Entry: Record "Cust. Ledger Entry";
    Total: Decimal;
begin
    Entry.SetRange("Customer No.", CustomerNo);
    if Entry.FindSet() then
        repeat
            Total += Entry.Amount;
        until Entry.Next() = 0;
    exit(Total);
end;

// ✅ CalcSums — single aggregation query at DB level
procedure GetTotalSales(CustomerNo: Code[20]): Decimal
var
    Entry: Record "Cust. Ledger Entry";
begin
    Entry.SetRange("Customer No.", CustomerNo);
    Entry.CalcSums(Amount);
    exit(Entry.Amount);
end;

Customer.SetLoadFields("Balance (LCY)");
Customer.Get(CustomerNo);
Customer.CalcFields("Balance (LCY)");   // required — not auto-calculated in code

// ✅ Temporary table — structured record data, multi-pass processing
procedure ProcessSalesData(var TempSalesLine: Record "Sales Line" temporary)
var
    SalesLine: Record "Sales Line";
begin
    SalesLine.SetLoadFields("No.", Quantity, "Unit Price", Amount);
    if SalesLine.FindSet() then
        repeat
            TempSalesLine := SalesLine;
            TempSalesLine.Insert();
        until SalesLine.Next() = 0;

    // Process in-memory — zero additional DB hits
    ApplyDiscounts(TempSalesLine);
    CalculateTotals(TempSalesLine);
end;

// ✅ Dictionary — key-value lookup cache
procedure CacheCustomerNames(): Dictionary of [Code[20], Text]
var
    Customer: Record Customer;
    Cache: Dictionary of [Code[20], Text];
begin
    Customer.SetLoadFields("No.", Name);
    if Customer.FindSet() then
        repeat
            Cache.Add(Customer."No.", Customer.Name);
        until Customer.Next() = 0;
    exit(Cache);
end;

// ✅ List — simple value collection
procedure GetBlockedCustomerNos(): List of [Code[20]]
var
    Customer: Record Customer;
    Result: List of [Code[20]];
begin
    Customer.SetRange(Blocked, Customer.Blocked::All);
    Customer.SetLoadFields("No.");
    if Customer.FindSet() then
        repeat
            Result.Add(Customer."No.");
        until Customer.Next() = 0;
    exit(Result);
end;

// ❌ Nested DB call inside loop — O(n²) database hits
if MainTable.FindSet() then
    repeat
        OtherTable.SetRange(Field, MainTable.Field);
        if OtherTable.FindSet() then          // DB call per iteration
            repeat
                // process
            until OtherTable.Next() = 0;
    until MainTable.Next() = 0;

// ✅ Pre-load into temp table, then join in memory
if OtherTable.FindSet() then
    repeat
        TempOther := OtherTable;
        TempOther.Insert();
    until OtherTable.Next() = 0;

if MainTable.FindSet() then
    repeat
        if TempOther.Get(MainTable.Field) then
            // process — no DB hit
    until MainTable.Next() = 0;

// ✅ Calculate all values first, then single Modify
procedure UpdateCustomerStats(CustomerNo: Code[20])
var
    Customer: Record Customer;
    TotalBalance: Decimal;
    LastPaymentDate: Date;
begin
    CalculateCustomerTotals(CustomerNo, TotalBalance, LastPaymentDate);

    Customer.SetLoadFields("Balance (LCY)", "Last Payment Date");
    if Customer.Get(CustomerNo) then begin
        Customer."Balance (LCY)" := TotalBalance;
        Customer."Last Payment Date" := LastPaymentDate;
        Customer.Modify(true);   // single write
    end;
end;

procedure UpdatePricesForItems(var Item: Record Item)
begin
    if Item.Count() > 1000 then
        UpdatePricesInBatches(Item)    // job queue / chunked
    else
        UpdatePricesDirectly(Item);
end;

❌ Circular dependency:
Table Customer: FlowField "Total Sales" → CalcFormula from Sales Statistics
Table Sales Statistics: FlowField "Customer Balance" → CalcFormula from Customer

Compiler error AL0896: recursive dependency detected