I have replied in the other thread. The gist is:

Import your data as individual points e.g. (long, lat) if that is how they are recorded.

You can then convert these to Points as a geometry type:

UPDATE imported_stuff SET g = geometry::STGeomFromText('POINT('+ CONVERT(VARCHAR,long) + ' ' + CONVERT(VARCHAR,lat) + ')',0);

Once you have the data imported like that you can use spatial aggregates (SQL2012+) to combine the data.

SELECT name, geometry::UnionAggregate(g) FROM imported_stuff GROUP BY name

Doing it this way gives you the most flexibility as you can filter the points by a where clause, group them etc.

To convert these all to lines rather than collections of points:

with lines as (

select name, g.ShortestLineTo(lead(g) over (partition by name order by rowid)) as LineToNext

from dbo.hurricanes

)

select name, geometry::UnionAggregate(LineToNext) as WholeRoute

from lines

group by name;