Using the READ UNCOMMITTED isolation level
A new client visits your bank to open an account. You insert her data into your system, causing a script like this one to start running:
BEGIN TRAN
INSERT INTO customers (first_name, last_name, email, phone)
VALUES ('Ann', 'Ros', '[email protected]', '555555555')
DECLARE @cust_id INT = scope_identity()
INSERT INTO accounts (account_number, customer_id, current_balance)
VALUES ('55555555555010121212', @cust_id, 150)
COMMIT TRAN
At that moment, your marketing colleague starts to send e-mails to every customer. There is going to be a raffle for a car! The script he executes gets every customer's data, including the last customer you inserted. This script starts running after the first insert occurs but before the COMMIT TRAN.
How can that be?
Este ejercicio forma parte del curso
Transactions and Error Handling in SQL Server
Instrucciones del ejercicio
- Set the
READ UNCOMMITTEDisolation level. - Select
first_name,last_name,emailandphonefromcustomerstable.
Ejercicio interactivo práctico
Prueba este ejercicio y completa el código de muestra.
-- Set the appropriate isolation level
___ TRANSACTION ___ LEVEL ___ ___
-- Select first_name, last_name, email and phone
SELECT
___,
___,
___,
___
FROM customers;