INSERT without duplicates in PostgreSQL?

Question

PostgreSQL

Good afternoon, there is a table:

Query example:

UPDATE users_data ud
    SET
        count = (ud.count + 1),
        updated_at = now()
    WHERE
        user_id = :uid AND
        command = :command AND
        created_at::date = :now;

INSERT INTO users_data (user_id, command)
    SELECT :uid, :command
    WHERE NOT EXISTS (
        SELECT 1
        FROM users_data
        WHERE
            user_id = :uid AND
            command = :command AND
            created_at::date = :now
        LIMIT 1
    );

But the following is happening, despite the fact that there is a unique index ..

Maybe someone will tell you what ..

Answer 1

207234 != 20725