Re: DBD::DB2: handling warnings

[Tim Bunce]

On Tue, Dec 30, 2008 at 12:37:05PM -0500, Hildo Biersma wrote:
 The DBD::DB2 driver does not handle warnings in a manner consistent with 
 other DBD drivers.  Specifically, if the trace level is lower than 3, 
 warnings are ignored; if the trace level is 3 or above, warnings are 
 treated like errors.  The driver also directly manipulates the DBI 
 internals instead of using DBIh_SET_ERR_CHAR.

 It treats all SQL_SUCCESS_WITH_INFO cases as warnings - perhaps these
 should be reported as informational events instead.

Yes, it should. (Just use  instead of 0.)

The DBI defaults PrintWarn to true, so if SQL_SUCCESS_WITH_INFO is
treated as a warning then they'll get printed - probably not what most
people would want.

Tim.

DBD::DB2: handling warnings

[Hildo Biersma]

The DBD::DB2 driver does not handle warnings in a manner consistent with 
other DBD drivers.  Specifically, if the trace level is lower than 3, 
warnings are ignored; if the trace level is 3 or above, warnings are 
treated like errors.  The driver also directly manipulates the DBI 
internals instead of using DBIh_SET_ERR_CHAR.


I have asked IBM to fix this and have received an internal defect number 
for this (166025); however, the latest DBD::DB2 release (1.3) does not 
include this feature.


The attached patch shows an attempt to fix this.  It works for me, but 
I'm not sure it is entirely correct; feedback from DBD::xxx authors and 
DBI experts would be welcome.


The patch basically removes the dependency on the trace level and rips 
out the direct manipulation of DBIc_err, errstr and state.  It treats 
all SQL_SUCCESS_WITH_INFO cases as warnings - perhaps these should be 
reported as informational events instead.


I hope IBM gets around to including this (or an improved version) in the 
next DBD::DB2 release; in the meantime, other users of DBD::DB2 may 
benefit from this change.


Cheers,
  Hildo Biersma
*** dbdimp.c.orig   Tue Dec 30 10:03:29 2008
--- dbdimp.cTue Dec 30 12:28:15 2008
***
*** 54,63 
  SQLINTEGER sqlcode;
  SQLCHAR sqlstate[6];
  SQLCHAR msgBuffer[SQL_MAX_MESSAGE_LENGTH+1];
! char *msg = NULL;
  SQLRETURN rec;
  
- 
  if( SQL_SUCCESS == rc )
return rc;
  
--- 54,62 
  SQLINTEGER sqlcode;
  SQLCHAR sqlstate[6];
  SQLCHAR msgBuffer[SQL_MAX_MESSAGE_LENGTH+1];
! char *msg = NULL, *err = NULL;
  SQLRETURN rec;
  
  if( SQL_SUCCESS == rc )
return rc;
  
***
*** 80,88 
  }
  }
  
- if( SQL_SUCCESS_WITH_INFO == rc  DBIS-debug  3 )
-   return SQL_SUCCESS;
- 
  if( handle != SQL_NULL_HANDLE )
  {
SQLRETURN rc;
--- 79,84 
***
*** 112,125 
msg = what ? what : ;
  }
  
! sv_setiv(DBIc_ERR(imp_xxh), (IV)sqlcode);
! sv_setpv(errstr, (char *)msg);
! sv_setpv(state,(char *)sqlstate);
! DBIh_EVENT2(h, ERROR_event, DBIc_ERR(imp_xxh), errstr);
! if (DBIS-debug = 2)
!   PerlIO_printf( DBILOGFP,
!  %s error %d recorded: %s\n,
!  what, rc, SvPV(errstr,na) );
  
  return( rc == SQL_SUCCESS_WITH_INFO ? SQL_SUCCESS : rc );
  }
--- 108,120 
msg = what ? what : ;
  }
  
! /* Report error or warning the DBI way */
! if (rc == SQL_SUCCESS_WITH_INFO) {
!   err = 0;  /* 0 = warning */
! } else {
!   err = Nullch;
! }
! DBIh_SET_ERR_CHAR(h, imp_xxh, err, sqlcode, msg, sqlstate, Nullch);
  
  return( rc == SQL_SUCCESS_WITH_INFO ? SQL_SUCCESS : rc );
  }
***
*** 141,149 
return rc;
  }
  
- if( SQL_SUCCESS_WITH_INFO == rc  DBIS-debug  3 )
-   return SQL_SUCCESS;
- 
  if( SQL_ERROR == rc || SQL_SUCCESS_WITH_INFO == rc )
  {
imp_sth_t *imp_sth;