====== PostgreSQL Blob ======
Postgress blob data type is "bytea", down read write example.
<code sql>
INSERT INTO "users" ("id", "name", "password", "permissions") VALUES (1, 'EugeneX', decode('5EFE2294ECD0EFF08EAB769FD2A6EE69', 'hex'), 0);
SELECT u.*, encode("password"::bytea, 'hex') as "pwhex" FROM "users" u;
TRUNCATE TABLE "users";
</code>