Hmm, intersting. I am using jdk 1.3.1, and pg74.213.jdbc2.jar driver, I hope this bug could be fixed in later version.
Thanks. Jie Liang -----Original Message----- From: Kris Jurka [mailto:[EMAIL PROTECTED] Sent: Thursday, June 17, 2004 3:26 PM To: Jie Liang Cc: Tom Lane; [EMAIL PROTECTED]; [EMAIL PROTECTED] 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 ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
