How can I convert from Double Precision to Bigint with PostgreSQL?

I need to convert a value of Double Precision to Bigint with PostgreSQL. How can I do that?

I have tried with to_bigint(myvalue) but that function didn't exist.

There are two ways to typecast in Postgres:

You either do it the SQL standard way:

select cast(3.141593 as bigint);

or you could use the Postgres-specific cast operator: ::

select (3.141593 :: bigint);

You might also want to consider the various rounding functions.

StackExchange Database Administrators Q#3429, answer score: 50