Re: Prepare Statement

Kris,
I have another question, I saw some discussion regarding
PreparedStatement work with array argument, I get a error when I try to
play with it.
E.g.
I have myfunction(int[]),
So,
PrepareStatement st = conn.prepareStatment("SELECT myfunction(?)");
String arr="{1,2,3}";
St.setString(1,arr};
Result rs = st.executeQuery();

Then it will complaint when it run:
Myfuntion(text) does not exist!

Did I miss something??

Thanks.

Jie Liang

-----Original Message-----
From: Kris Jurka [mailto:books(at)ejurka(dot)com]
Sent: Thursday, June 17, 2004 3:26 PM
To: Jie Liang
Cc: Tom Lane; pgsql-sql(at)postgresql(dot)org; pgsql-jdbc(at)postgresql(dot)org
Subject: Re: [JDBC] Prepare Statement

On Thu, 17 Jun 2004, Jie Liang wrote:

> Kris,
> You are right, I modified that piece of code a little bit,
> CallableStatement stmt = conn.prepareCall("{?=call chr(?)}"); Then my
> log file were: Select * from chr(65) as result;
> Select * from chr(66) as result;
> ......
> However, if I use:
> PrepareStatement stmt = conn.prepareStatement("SELECT chr(?)");
> Then my log file are same as yours.i.e. it use PREPARE and EXECUTE.
>
> So, I am getting confusion.
> I think CallableStatement is extended from PrepareStatement, it should

> have same behaviou.
>

What's happening here is that you can only use prepared statements for
certain operations. You can't for example prepare a CREATE TABLE
statement. The driver examines the query to see if it is valid for
preparing and I believe the problem here is that with a callable
statement
it is examinging the query with "call" before it is transformed to a
SELECT, so it doesn't recognize it as a preparable. This looks like a
bug
to me.

Kris Jurka