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

I think you may need to use multiple updates.

Something like (not tested):

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

Ugly though.

That example's T-SQL, but I think MySql has equivalents to everything used.