Why is a column that can be null assigned sql.NullString?

[mwbidwell]

CREATE TABLE users (
id bigserial PRIMARY KEY,
first_name VARCHAR(255),
last_name VARCHAR(255),
email VARCHAR(255) NOT NULL,
password VARCHAR(255) NOT NULL,
created_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
updated_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP
);

-- name: GetUserByID :one
SELECT * FROM users
WHERE id = $1 LIMIT 1;

Generates this:
type User struct {
ID int64
FirstName sql.NullString
LastName sql.NullString
Email string
Password string
CreatedAt sql.NullTime
UpdatedAt time.Time
}

[mwbidwell]

Hmm... seems like I just misunderstood what sql.NullString is used for.

Please disregard.