Muhammad al-xorazmiy nomidagi toshkent axborot texnologiyalari universiteti mustaqil-1-2-3-4-5
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- SAVEPOINT tranzaksiyasini ishlatilishi
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-- Begin Transaction BEGIN; -- Savepoint SAVEPOINT before_complex_query; BEGIN TRY -- Complex query, you can replace this with your actual query UPDATE Products SET price = price * 1.1 WHERE category = 'Electronics'; -- Simulate an error, for example, a constraint violation INSERT INTO Products (name, category, price) VALUES ('New Product', 'Clothing', 25.99); EXCEPTION -- If an error occurs, rollback to the savepoint WHEN OTHERS THEN ROLLBACK TO SAVEPOINT before_complex_query; -- Optionally handle or log the error RAISE NOTICE 'An error occurred: %', SQLERRM; END TRY; -- If no error occurred, commit the transaction COMMIT; -- Mijozlarni o'zgartirish UPDATE customers SET email = 'new_email@example.com' WHERE last_name = 'Smith' AND phone_number LIKE '+998%'; -- Buyurtmalarni o'zgartirish UPDATE orders SET total_amount = 2000 WHERE customer_id IN (SELECT customer_id FROM customers WHERE last_name = 'Smith'); SAVEPOINT tranzaksiyasini ishlatilishi -- Begin Transaction BEGIN; -- Savepoint SAVEPOINT before_complex_transaction; BEGIN TRY -- Complex transaction, you can replace this with your actual logic -- Update prices of products in the 'Electronics' category UPDATE Products SET price = price * 1.1 WHERE category = 'Electronics'; -- Savepoint SAVEPOINT after_price_update; -- Insert a new product INSERT INTO Products (name, category, price) VALUES ('New Product', 'Clothing', 25.99); -- Commit the transaction COMMIT; EXCEPTION -- If an error occurs, rollback to the savepoint WHEN OTHERS THEN ROLLBACK TO SAVEPOINT after_price_update; -- Optionally handle or log the error RAISE NOTICE 'An error occurred: %', SQLERRM; -- Rollback the entire transaction (excluding the price update) ROLLBACK TO SAVEPOINT before_complex_transaction; END TRY; Download 131.16 Kb. Do'stlaringiz bilan baham: |
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