Re: JDBC_FreeResult - Free resultset and preparedStatement

["hockchai Lim" <lim.hock-chai@xxxxxxxxxxxxxxx>]

Thanks Scott, I must miss interpreted the code.

I'll dig more into the cause of the problem that I'm encountering below:

I've a sub-proc with code like this:
  JDBC_SetLong(addressSelectPS(connIdx) :1 :piWGINTS.unii);
  myRS = JDBC_ExecPrepQry(addressSelectPS(connIdx));
  if myRS <> *null;
    if jdbc_nextRow(myRS);
      myRecExist = *on;
    endif;
    JDBC_FreeResult(myRS);
  endif;


This sub-proc works fine on the first execution.  But it get error below 
when it is executed on the second time.  The error happened when it executes 
the JDBC_SetLong(addressSelectPS(connIdx) :1 :piWGINTS.unii).

java.lang.NullPointerException
 at java.lang.Throwable.<init>(Throwable.java:181)
 at java.lang.RuntimeException.<init>(RuntimeException.java:32)
 at java.lang.NullPointerException.<init>(NullPointerException.java:36)
 at com.mysql.jdbc.PreparedStatement.set(Unknown Source)
 at com.mysql.jdbc.PreparedStatement.setLong(Unknown Source)


The RPG error (joblog) shows this:
Message ID . . . . . . :   RNX0301       Severity . . . . . . . :   50
Message type . . . . . :   Escape
Date sent  . . . . . . :   09/08/10      Time sent  . . . . . . :   11:16:58

Message . . . . :   Java exception received when calling Java method.
Cause . . . . . :   RPG procedure JDBC_SETLO in program SVCPGM/JDBCR4 
received
  Java exception "java.lang.NullPointerException:" when calling method
  "setLong" with signature "(IJ)V" in class "java.sql.PreparedStatement".
Recovery  . . . :   Contact the person responsible for program maintenance 
to
  determine the cause of the problem.
Technical description . . . . . . . . :   If the exception indicates that 
the
  Java class was not found, ensure the class for the method is in the class
  path. If the exception indicates that the Java method was not found, check
  the method name and signature. If the signature is not correct, change the
  RPG prototype for the method, or change the Java method, so that the 
return
  type and parameter types match. You can determine the signatures for all 
the


"Scott Klement" <rpg400-l@xxxxxxxxxxxxxxxx> wrote in message 
news:mailman.6320.1283960007.2619.rpg400-l@xxxxxxxxxxxxxxx
> I don't agree with your assessment.
>
> It closes the current statement -- i.e. it releases the database resources 
> it's currently using, so the database manager will stop processing the SQL 
> statement that you executed, and free up it's memory.
>
> It doesn't free the PreparedStatement object you created!  It doesn't 
> prevent you from inserting new parameter markers and running it again! It 
> just closes the previous run so you aren't running BOTH.
>
>
> On 9/8/2010 9:51 AM, hockchai Lim wrote:
> > I just did some studying on Scott Klement's JDBC_FreeResult export
> > procedure.  In observing the code, it seems like this procedure not only
> > closes and frees the ResultSet, it also auto closes and frees  the
> > PreparedStatement object that is associated to the ResultSet.
> >
> > I've wrote a RPG program that needs to a same PreparedStatment object to
> > perform different queries using different parameter mark values.  So, I
> > really do not want to free the PreparedStatement object when freeing the
> > ResultSet.  Does anyone know of the best way to handle this?
> >
> > Thanks