I had earlier shown how to do an update query based on a field from another table in MS Access. Here is the syntax for postgres:

UPDATE to_table SET to_column = from_column from from_table where to_table.primary_key= from_table.foreign_key;

handy notes for this query:

• append in postgres is || (double pipe)
• cast in postgres is like column_to_cast::type_to_cast