Your first error-handling script

You realized your products table doesn't have any constraint to check the data stored in its stock column. It makes sense that stock is always greater than or equal to 0. For some reason, there is a mistake in the following row. The stock is -1!

| product_id | product_name | stock | price |
|------------|--------------|-------|-------|
| 6          | Trek Neko+   | -1    | 2799  |

You want to prepare a script adding a constraint to the products table, so that only stocks greater than or equal to 0 are allowed.

If you add this constraint that only allows stocks greater than or equal to 0, the execution will fail because there is one row where the stock equals -1.

How can you prepare the script?

Diese Übung ist Teil des Kurses

Transactions and Error Handling in SQL Server

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Anleitung zur Übung

Surround the constraint with a TRY block.
Add the constraint to the products table.
Surround the error message with a CATCH block.

Interaktive Übung

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-- Set up the TRY block
BEGIN ___
	-- Add the constraint
	ALTER TABLE ___
		ADD CONSTRAINT CHK_Stock CHECK (stock >= 0);
___ ___
-- Set up the CATCH block
___ ___
	SELECT 'An error occurred!';
END ___

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