Use AL to Extend Business Central MB-820 Practice Questions (Page 5)

Questions 21–25

1. 21application · medium

   A developer is writing a procedure that calculates the total price of a sales order, including a discount that is applied only if the order total exceeds a certain threshold. The developer uses the following expression: TotalPrice := IF Subtotal > 1000 THEN Subtotal * 0.9 ELSE Subtotal;. Which data type should the variable TotalPrice be?

   • ABoolean
   • BInteger
   • CText
   • DDecimal
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2. 22expert · hard

   A developer is creating an AL extension that exports sales orders to a file. The file must be saved to a network share that is accessible from the Business Central server. The developer needs to ensure that the file is written atomically so that other processes do not read a partially written file. Which approach should the developer use?

   • AUse File.Copy() to copy the file from a local path to the network share.
   • BWrite the file to a temporary location and then use File.Move() to move it to the network share.
   • CWrite the file directly to the network share using File.WriteText().
   • DUse File.Upload() to upload the file to the network share.
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4. 23application · medium

   A developer is writing AL code to delete all sales lines for a given sales order. The code must be efficient and handle the case where there are no lines. Which approach should the developer use?

   • AUse the Delete method on the Sales Line table without a filter.
   • BUse the DeleteAll method on the Sales Line table with a filter.
   • CUse a loop with FindSet and Delete on each record.
   • DUse the Modify method to set a flag and then delete.
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5. 24application · medium

   A developer is extending a Business Central extension that processes incoming sales orders. The current code inserts a Sales Header record and then calls a custom procedure to calculate discounts. If the discount calculation fails, the Sales Header record remains inserted, causing orphaned data. The developer needs to ensure that if any error occurs during the order processing, all changes are rolled back. What should the developer do?

   • AUse the Codeunit.Run() method to execute the discount calculation in a separate transaction.
   • BCall the discount calculation procedure before inserting the Sales Header record.
   • CPlace the insert and the discount calculation inside a single codeunit and call it with the Codeunit.Run() method.
   • DWrap the insert and the discount calculation in a try-catch block and call Error() in the catch section.
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6. 25expert · hard

   A developer is writing a codeunit that updates inventory quantities for multiple items. The update process must be efficient and minimize locking conflicts. The developer needs to update the quantity for each item based on a temporary table of changes. Which approach should the developer use?

   • AUse the MODIFY function on each item record in a loop.
   • BUse the INSERT function to create new records for each change.
   • CUse the MODIFYALL function to update all items at once.
   • DUse the DELETE function to remove old records and then insert new ones.
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