CREATE TABLE UserGroup
(
    UserID uniqueidentifier not null,
    GroupID uniqueidentifier not null
)

INSERT INTO #storegroupdata
(OwnerID, GroupList)
select B.UserID, @temp = COALESCE(@temp + ',', '') + CAST(g.GroupName as nvarchar(200))
from appSec.dbo.UserGroup ug
inner join appSec.dbo.[Group] g on g.GroupID = ug.GroupID
inner join app.dbo.User B on B.UserID = ug.UserID