Updating table with GeometryFromText of PostGIS

Question

I'm trying to update a column public_geometry in a table by creating a point from longitude and latitude cols from the same table. The database is PostgreSQL with Pgadmin as program to handle the databasse:

 UPDATE sirene_test.etablisssement_actif
SET geom=ST_GeometryFromText('POINT('|| latitude  ||' '|| longitude ||')', 4326);

I got this Error :

ERREUR:  parse error - invalid geometry
HINT:  "POINT( )" <-- parse error at position 9 within geometry
********** Erreur **********

ERREUR: parse error - invalid geometry
État SQL :XX000
Astuce : "POINT( )" <-- parse error at position 9 within geometry