How to fix Raise exception in PostgreSQL

-- Correct: 2 placeholders, 2 arguments
RAISE EXCEPTION 'User % not found with status %', user_id, status;

-- Wrong: 2 placeholders, 1 argument
RAISE EXCEPTION 'User % not found with status %', user_id;

-- Correct: Inside a function
CREATE OR REPLACE FUNCTION check_user(user_id INT)
RETURNS VOID AS $$
BEGIN
    IF NOT EXISTS (SELECT 1 FROM users WHERE id = user_id) THEN
        RAISE EXCEPTION 'User % does not exist', user_id;
    END IF;
END;
$$ LANGUAGE plpgsql;

-- Wrong: Direct use in SQL
RAISE EXCEPTION 'Invalid input'; -- Will fail

-- Correct: USING clause with multiple options
RAISE EXCEPTION 'Duplicate user ID: %', user_id
    USING HINT = 'Please provide a unique user ID',
          ERRCODE = 'unique_violation';

-- Wrong: Missing USING keyword
RAISE EXCEPTION 'Invalid input'
    HINT = 'Check your parameters';

-- Correct: Using standard SQLSTATE
RAISE EXCEPTION 'Invalid age' USING ERRCODE = '22003';

-- Correct: Using custom error code
RAISE EXCEPTION 'Business logic error' USING ERRCODE = 'A0001';

-- Wrong: Invalid format
RAISE EXCEPTION 'Error' USING ERRCODE = 'INVALID';

CREATE OR REPLACE FUNCTION safe_operation()
RETURNS VOID AS $$
BEGIN
    -- Some operation that might fail
    PERFORM * FROM invalid_table;
EXCEPTION
    WHEN undefined_table THEN
        -- Re-throw the same error
        RAISE;
END;
$$ LANGUAGE plpgsql;