Re: [GENERAL] timestamps

strawman(at)plexi(dot)com ha scritto:

> I'm trying to create a column that defaults to the current time and date. I
> tried the SQLServer like syntax below but potgresql choked:
>
> CREATE TABLE clicks (
> avo_userid varchar (10) NOT NULL ,
> link_id int NOT NULL ,
> the_time timestamp NOT NULL CONSTRAINT df_now DEFAULT (timestamp('now'))
> );
> NOTICE: there is more than one function named "timestamp"
> NOTICE: that satisfies the given argument types. you will have to
> NOTICE: retype your query using explicit typecasts.
> ERROR: function timestamp(unknown) does not exist
>
> Is "timestamp" not both a type and a function? How can I look it up?
>

>

You can create table like:

CREATE TABLE clicks (
userid varchar(10) not null,
links int not null,
df_time timestamp constraint df_now DEFAULT current_timestamp
);

but remember in such case you can insert a value to df_time column different
than current timestamp.
If you want to avoid this you have to create a trigger (see attached example).

--

>
> And one more question: How does one construct a foreign key relationship in
> postgres?
>
> Thanks for any help.

Foreign key is not yet implemented but you may use triggers (See attached
example).

NB: You need v6.4.? to use examples.

--
- Jose' -

"No other success in life can compensate for failure in the home" (David O.
McKay)