Hi,
Sorry it is not 'database' ,but 'table' . I followed the syntax given
UPDATE table_name SET(columns) FROM (SELECT columns FROM table_2) AS som-val WHERE condition;
And I tried it in psql command line as
my_db=# update test set id=g.id2 from (select id2 from test2)as g ;
UPDATE 0
where my_db is the database I created.
regards
archana