Re: Problem in release connection

[Bernt M. Johnsen]

Hi,

Maybe it would help to close the prepared statement befor you close
the connection, which also would be the natural way of cleaning up.

Bernt

 Shambhu wrote (2007-03-21 18:55:29):
 Hi,
 
 I am using Cloudscape(IBM Cloudscape Version 10.1) and derbyclient.jar
 provided by derby. Following are the code I am using for clean the database
 connection and also PreparedStatement. 
 
  
 
 public void cleanup(Connection aoConnection,
 
 PreparedStatement aoPreparedStatement)  {
 
 try{
 
 if(!(aoConnection ==null || aoConnection.isClosed()))
 
 aoConnection.close();//Release Connection
 
 if(aoPreparedStatement != null)
 
 aoPreparedStatement.close();
 
 }catch(SQLException aoSQLException){
 
 aoSQLException.printStackTrace();
 
 }
 
 }
 
  
 
 But some time this method call get hang. Can any one tell me why it is
 happening?
 
  
 
 I have one more problem with this database. I am updating a table using
 following code.
 
  
 
 //Table create script
 
 CREATE TABLE TABLE_MEMORY (
 
 MEMORY_ID BIGINT NOT NULL GENERATED ALWAYS AS
 IDENTITY,
 
 MEMORY SMALLINT,
 
 PRIMARY KEY (MEMORY_ID)
 
 );
 
  
 
 //JAVA Code
 
 Connection aoConnection = getConnection();
 
 PreparedStatement  psUpdate = aoConnection.prepareStatement(UPDATE
 TABLE_MEMORY SET MEMORY=? WHERE MEMORY_ID=?);
 
 psUpdate.setInt(counter++, 38650);
 
 psUpdate.setInt(counter++, 15254);
 
 int updated = psUpdate.executeUpdate();
 
  
 
 If I run above code, executeUpdate method does not throw any exception and
 always returns value 1. But, due to size of value I am setting (38650) is
 more than size of smallint, so it does not update database.
 
 Can any one tell me why value return by executeUpdate method is 1 even
 database update is failed?
 
  
 
 For any reply thanks in advance.
 
  
 
 Thanks  Regards
 
 Shambhu Kumar Sinha
 
  
 

-- 
Bernt Marius Johnsen, Database Technology Group, 
Staff Engineer, Technical Lead Derby/Java DB
Sun Microsystems, Trondheim, Norway


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Re: Problem in release connection

[Bryan Pendleton]

provided by derby. Following are the code I am using for clean the 
database connection and also PreparedStatement.


if(!(aoConnection ==null || aoConnection.isClosed()))
aoConnection.close();//Release Connection
if(aoPreparedStatement != null)
aoPreparedStatement.close();


I think it would be better to close the statement before
you close the connection.

I also tend not to bother with calling isClosed methods. Instead
I set the variable to null after I close the connection. I think
that might also help the garbage collector find more garbage to
collect.

So I'd write something more like:

  if (aoPreparedStatement != null)
  {
aoPreparedStatement.close();
aoPreparedStatement = null;
  }
  if (aoConnection != null)
  {
aoConnection.close();
aoConnection = null;
  }

thanks,

bryan