Re: [GENERAL] CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP

sheila bel wrote:

> Hi all,
>
> I wanted to get some information about date and time
> stamps and examples of how to use them. In the User
> Manual I got referred to functions called CURRENT_DATE,
> CURRENT_TIME. I have been literally searching for
> hours to find more about them in all the PostgreSQL
> manuals, I've used ALL the search engines and did not
> find anything. If there is a reference to them they should
> be somewhere in there, right?
> I'm sorry but dear developers your manual is not user
> friendly at all :(
> A lot of time gets wasted on finding the information you
> need or not finding them at all.
>
> -Sheila

You ca use the niladics datetime functions:

- CURRENT_DATE
- CURRENT_TIME
- CURRENT_TIMESTAMP

as a column default value like:

CREATE TABLE mytb (
mydt DATE DEFAULT CURRENT_DATE,
mytm TIME DEFAULT CURRENT_TIME,
myts TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

to insert a value into a column as in:

INSERT INTO mytb (mydt) VALUES(CURRENT_DATE);

to compare two values as in:

SELECT * FROM mytb WHERE mytm BETWEEN '1999-12-31 12:30:00' AND
CURRENT_TIMESTAMP;

etc, etc...

--
Jose' Soares
Bologna, Italy Jose(at)sferacarta(dot)com