JDBC - Prepared statements and PostgreSql Time/Date operations

Hi Jan
how about casting the parameter to date format e.g.

select * from mytable where creation_time > (CURRENT_TIMESTAMP - $1::date)

Anyone?
M--
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----- Original Message -----
From: Jan Bilek
To: pgsql-general@postgresql.org
Sent: Friday, May 18, 2007 4:39 PM
Subject: [GENERAL] JDBC - Prepared statements and PostgreSql Time/Date operations

Hello,

I've got following problem:

I use this simple query:

select * from mytable where creation_time > (CURRENT_TIMESTAMP - interval '7 days');

---> it selects all rows from mytable, which were created before one week or sooner (creation_time is column in mytable).

I would like to use this query in java PreparedStatement, where age of a row would be one of its parameters:

PreparedStatement could look like this:
select * from mytable where creation_time > (CURRENT_TIMESTAMP - ?)

But nothing works with PreparedStatements!
I tried to set whole interval strings "interval '7 days'" as a parameter
I tried to set time strings '7 days' as a parameter
I tried to use BigDecimal as a parameter...

So, my question is: how to dynamically set time interval values to PreparedStatements and how to apply them to my example?
I've searched PostgreSql and Java docs, but i haven't find any cure.

Thanks for help.

JB

"Jan Bilek" <bilekj@gmail.com> writes:

I would like to use this query in java PreparedStatement, where age of a =
row would be one of its parameters:

PreparedStatement could look like this:
select * from mytable where creation_time > (CURRENT_TIMESTAMP - ?)

But nothing works with PreparedStatements!
I tried to set whole interval strings "interval '7 days'" as a parameter
I tried to set time strings '7 days' as a parameter
I tried to use BigDecimal as a parameter...

I'm not sure that Java has a type corresponding to "interval". Instead
use number-times-interval multiplication:

... creation_time > (CURRENT_TIMESTAMP - ? * interval '1 day')

The parameter is now of plain integer or float type.

regards, tom lane

Got it!

"Jan Bilek" <bilekj@gmail.com> writes:

I would like to use this query in java PreparedStatement, where age of a
=
row would be one of its parameters:

PreparedStatement could look like this:
select * from mytable where creation_time > (CURRENT_TIMESTAMP - ?)

But nothing works with PreparedStatements!
I tried to set whole interval strings "interval '7 days'" as a parameter
I tried to set time strings '7 days' as a parameter
I tried to use BigDecimal as a parameter...

I'm not sure that Java has a type corresponding to "interval". Instead
use number-times-interval multiplication:

... creation_time > (CURRENT_TIMESTAMP - ? * interval '1 day')

Integer-interval multiplication is the way!!!
Many thanks for quick help.

(Java seems not to have oracle/postgre interval type)