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What Happens When You Add NULL And Integer
Question
What happens when you add a NULL value and an integer?
Answer
You get an error.
-- Drop table if exists
DROP TABLE IF EXISTS names;
-- Create table called names
CREATE TABLE names (
-- string variable
name varchar(255),
-- integer variable
score int
)
-- Insert into the table
INSERT INTO names (name, score)
-- two rows
VALUES
(NULL, 1),
('Tommy', 1)
-- Add a column with a NULL value and a integer
SELECT
name + score as results
FROM names
[42883] ERROR: operator does not exist: character varying + integer Hint: No operator matches the given name and argument type(s). You might need to add explicit type casts. Position: 17