PostgreSQL Update the JSONB column using another list

Column | Type | Modifiers < br />------------+-----------------------------+---- -------------------------------------------------- --
 id | integer | not null default nextval('merchants_id_seq'::regclass)
 name | character varying | not null
 nameb | jsonb | not null default'{}':: jsonb

name | nameb 
----------------- ---------------------+------------
 hello | {} 
 world | {} 

name | nameb 
-------------------- ------------------+------------
 hello | {"en": "hello"}
 world | {"en": "world"}

I want to put the data from one column (varchar ) Migrate to another column (jsonb)

Column | Type | Modifiers 
------------+--- --------------------------+----------------------- ---------------------------------
 id | integer | not null default nextval('merchants_id_seq': :regclass)
 name | character varying | not null
 nameb | jsonb | not null default'{}'::jsonb

So nameb will become {“en”: “$ name”}, where $name is the value in the name field.

For example:

SELECT name,nameb

Before:

name | nameb 
-------------------------------- ------+------------
 hello | {} 
 world | {}

After:

name | nameb 
----------------------------------- ---+------------
 hello | {"en": "hello"}
 world | {"en": "world"}

Using regualar type I can do UPDATE SET whatever =(SELECT …), but how to do it with jsonb?

UPDATE Merchant SET nameb =(SELECT'{“en”:”fillme!”}’:: jsonb);It works, but how to set the value of “fillme!” in another field?

I found a solution

UPDATE merchants AS m1 
SET nameb = (
 SELECT row_to_json(t) FROM (
 SELECT name as en FROM merchants AS m2 WHERE m1.id = m2.id
) t
)::jsonb; 

Not sure if it is correct, but it does work