Insert data into particular rows/columns

Update Version

PL/pgSQL

UPDATE table1 
   SET col1 = othertable.col2,
       col2 = othertable.col3 
  FROM othertable 
 WHERE othertable.col1 = 123;

INSERT Version

Text

INSERT INTO table1 (col1, col2) 
SELECT col1, col2 
  FROM othertable