How can I insert values into a table, using a subquery with more than one result?

You want:

insert into prices (group, id, price)
select 
    7, articleId, 1.50
from article where name like 'ABC%';

where you just hardcode the constant fields.

Try this:

INSERT INTO prices (
    group, 
    id,
    price
) 
SELECT
    7,
    articleId,
    1.50
FROM
    article 
WHERE 
    name LIKE 'ABC%';

INSERT INTO prices (group, id, price)
  SELECT 7, articleId, 1.50 FROM article WHERE name LIKE 'ABC%'

Related