So gießen Sie Datentypen in PostgreSQL

CAST( expression AS target_type); 
-- example) extract from String into an integer
SELECT CAST('500' AS INTEGER);
--  or 
expression :: type
-- example) extract from '2019-07-13 1:20:50' to '2019-07-13'
SELECT '2019-07-13 1:20:50'::TIMESTAMP::DATE;
Lux