[Qgis-user] field calculator: geomToWTK

[Bernd Vogelgesang]

Hi,
I found it the fastest way to use the geomtoWTK function in the field 
calculator to export the geometry of a polygon layer to a text field 
(geomToWTK($geometry)), join it to a database table (dbf), export it as 
csv and then have a new layer (many database entries for one geometry, 
resulting in duplicate geometries) imported with Delimited Text Layer.

This worked fione and fast for one task, but now I have way too long WTK 
to store it in a text field.

One reason for this is, that the precision of the exported nodes is 17 
digits, which bloates the hole string. For my task zero precision would 
be sufficient.
Example:
POLYGON((4440571.01020000036805868 5572180,4440570.52076516300439835 
5572176.90983005613088608,4440569.1003699442371726 ...))

Question: Is there a way to influece the output of the WTK, so I have 
zero digits precision?
or
Can anyone recommend another workflow?

Cheers
Bernd