Skip site navigation (1) Skip section navigation (2)

Re: Prepare Statement

From: "Jie Liang" <jie(at)stbernard(dot)com>
To: "Kris Jurka" <books(at)ejurka(dot)com>
Cc: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>, <pgsql-sql(at)postgresql(dot)org>,<pgsql-jdbc(at)postgresql(dot)org>
Subject: Re: Prepare Statement
Date: 2004-06-18 03:09:16
Message-ID: E7E213858379814A9AE48CA6754F5ECB0345194D@mail01.stbernard.com (view raw or flat)
Thread:
Lists: pgsql-jdbcpgsql-sql
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


Responses

pgsql-sql by date

Next:From: Kris JurkaDate: 2004-06-18 05:47:19
Subject: Re: Prepare Statement
Previous:From: Jie LiangDate: 2004-06-17 22:50:33
Subject: Re: Prepare Statement

pgsql-jdbc by date

Next:From: Kris JurkaDate: 2004-06-18 05:47:19
Subject: Re: Prepare Statement
Previous:From: Barry LindDate: 2004-06-18 02:13:02
Subject: Re: Nested transactions

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group