How tnaslate kode from MySQL to Postgres?

I create universal module to use databases. MySQL haw extra method
AUTO_INCREMENT and function LAST_INSERT_ID().

CREATE TABLE baza (
  id integer unsigned NOT NULL auto_increment PRIMARY KEY,
  id_parent integer unsigned NOT NULL,
  id_children integer unsigned NOT NULL,
  data    blob );

INSERT INTO baza (id_parent,id_children,data) VALUES (0,0,"text");
UPDATE baza SET id_parent=LAST_INSERT_ID() WHERE id=LAST_INSERT_ID();

Question:
How create this method in Postgres?
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WRaq