Add MySQL Unix_timestamp and from_unixtime functions to PostgreSQL

MySQL's 2 commonly used functions Unix_timestamp () and From_unixtime PostgreSQL are not available, but with PostgreSQL's powerful extensibility It is easy to solve problems.

Words far away, in front of the eyes, the document look carefully, the question Ren solution. PostgreSQL questions for extract and date_part to take epoch
That
Unix_timestamp () = Round (Date_part (' Epoch ', Now ()))
From_unixtime (int) = To_timestamp (int)

Add function Unix_timestamp ()
CREATE FUNCTION unix_timestamp () RETURNS integer as $$
SELECT (Date_part (' Epoch ', Now ())):: integer;
$$ LANGUAGE SQL immutable;

Add function From_unixtime ()
CREATE FUNCTION from_unixtime (int) RETURNS timestamp as $$
SELECT To_timestamp ($):: timestamp;
$$ LANGUAGE SQL immutable;

Add MySQL Unix_timestamp and from_unixtime functions to PostgreSQL