Logging messages on specific exceptions
One of the best uses of catching multiple specific exception is to distinctly handle and log unique error message that help you understand exactly why an exception occurred. Let's apply this in a scenario where both error conditions are possible. We'll discuss after the exercise why it capture the specific message it did.
Cet exercice fait partie du cours
Transactions and Error Handling in PostgreSQL
Instructions
- Build an exception handler for a
not_null_violation. - Insert
"failed to insert"as themsg,Glucose can not be null.as thedetailinto theerrorstable if anot_null_violationoccurs.
Exercice interactif pratique
Essayez cet exercice en complétant cet exemple de code.
-- Make a DO function
DO $$
-- Open a transaction block
___
INSERT INTO patients (a1c, glucose, fasting) values (20, null, TRUE);
-- Catch an Exception
EXCEPTION
-- Make it catch check_violation exception types
WHEN check_violation THEN
-- Insert the proper msg and detail
INSERT INTO errors (msg, detail)
VALUES ('failed to insert', 'A1C is higher than clinically accepted norms.');
-- Make it catch not_null_violation exception types
___ ___ ___
-- Insert the proper msg and detail
INSERT INTO errors (msg, detail)
___ (___, ___);
END$$;
-- Select all the errors recorded
SELECT * FROM errors;