Concatenate several fields into one with SQL

Question

I have three tables tag, page, pagetag

With the data below

page

ID      NAME
1           


        

Answer 1

Sergio del Amo:

However, I am not getting the pages without tags. I guess i need to write my query with left outer joins.

SELECT pagetag.id, page.name, group_concat(tag.name)
FROM
(
    page LEFT JOIN pagetag ON page.id = pagetag.pageid
)
LEFT JOIN tag ON pagetag.tagid = tag.id
GROUP BY page.id;

Not a very pretty query, but should give you what you want - pagetag.id and group_concat(tag.name) will be null for page 4 in the example you've posted above, but the page shall appear in the results.