concatenate several fields into one with SQL

ID      NAME
1       page 1
2       page 2
3       page 3
4       page 4

ID      NAME
1       tag 1
2       tag 2
3       tag 3
4       tag 4

ID   PAGEID  TAGID
1    2        1
2    2        3
3    3        4
4    1        1
5    1        2
6    1        3

ID      NAME       TAGS
1       page 1     tag 1, tag 2, tag 3
2       page 2     tag 1, tag 3
3       page 3     tag 4
4       page 4

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;

SELECT page_tag.id, page.name, group_concat(tags.name) FROM tag,page, page_tag
where page_tag.page_id = page.page_id AND page_tag.tag_id = tag.id;

SELECT page.id AS id, page.name AS name, tagstable.tags AS tags FROM page
LEFT OUTER JOIN
(SELECT pagetag.pageid, GROUP_CONCAT(distinct tag.name) as tags FROM tag INNER JOIN pagetag ON tagid=tag.id GROUP BY pagetag.pageid) AS tagstable ON tagstable.pageid=page.id GROUP BY page.id

id   name    tags
---------------------------
1    page 1  tag2,tag3,tag1
2    page 2  tag1,tag3
3    page 3  tag4
4    page 4  NULL

select ID as 'PageId', Name as 'PageName', null as 'Tags'
into #temp
from [PageTable]

declare @lastOp int
set @lastOp = 1

while @lastOp > 0
begin
    update p
    set p.tags = isnull(tags + ', ', '' ) + t.[Tagid]
    from #temp p
        inner join [TagTable] t
            on p.[PageId] = t.[PageId]
    where p.tags not like '%' + t.[Tagid] + '%'

    set  @lastOp == @@rowcount
end

select * from #temp

select COALESCE(pagetag.id, '') AS id ...