Re: There's an error, but $sth->execute returns -1

[email protected] ("Martin J. Evans")
Newsgroups perl.dbi.users
Message-ID <[email protected]>
  On 16/10/2010 11:03, Martin J. Evans wrote:
>  On 15/10/2010 22:20, Roode, Eric wrote:
>> Hello all,
>>
>>
>>
>> DBI docs says that statement handle method execute() returns undef on
>> error.  I have found a situation where that does not hold.  Was hoping
>> someone could help me out, maybe there's a workaround.
>>
>>
>>
>> First, I'm running ActiveState Perl 5.10.0 on Windows 7, connecting to a
>> SQL Server 2000 database on a different machine.  I have DBI version
>> 1.613, and DBD::ODBC version 1.24.
>>
>>
>>
>> In a nutshell, here is what happens.  I connect to the database, using
>> the ODBC driver, and setting RaiseError to 1 and PrintError to 0.  I
>> prepare a statement which calls a procedure.  I bind parameters to the
>> statement (some input, some output, various types), I call execute().
>>
>>
>>
>> There's a problem with one of the parameters; because of that, the
>> stored procedure tries to insert a null value into a column that does
>> not accept nulls.  So SQL Server gives an error ("Cannot insert the
>> value NULL into column 'enabled'"), and the DBI system stores this
>> string in errstr.  However, the execute() method returns -1, which is
>> what it would return on success.  Also, no error is thrown (I have the
>> $sth->execute call wrapped in an eval, and $@ is empty afterward).
>>
>>
>>
>> You can see the definition of the table and the stored procedure at
>> http://nopaste.gamedev.pl/?id=8272.
>>
>> The Perl code that demonstrates the problem is at
>> http://nopaste.gamedev.pl/?id=8273.
>>
>> And the DBD trace output is at http://nopaste.gamedev.pl/?id=8274.
>>
>>
>>
>> I hope someone can shed some light on what's going on here.  Should I
>> check errstr and ignore the return value? Thanks in advance.
>>
>> Eric
>>
>>
>>
> (Tim Bunce, if you see this could you clarify what dbd_st_execute is 
> supposed to return as I could not find the full details in DBI::DBD. 
> It would appear DBD::ODBC returns -2 for error, -1 for rowcount not 
> known and a positive number for rows affected).
>
> The status returned was SQL_SUCCESS_WITH_INFO:
>
> !!dbd_error2(err_rc=1, what=st_execute/SQLExecute, 
> handles=(3194c98,2b5a848,30d4cd0)
>
> that err_rc=1 which is not an error.
>
> If SQLRowCount returns -1 then dbd_st_execute will return -1, that may 
> be a bug but really the code should not have got to this point anyway. 
> The are differences between what DBI documents for the execute method 
> and what DBD::ODBC returns from the dbd_st_execute and I cannot see 
> for instance the -2 (for errors) documented in DBI::DBD so I'm not 
> sure if this is right or wrong (Tim?).
>
> As far as I can see this looks like a bug in your driver (but I'll try 
> and reproduce here). Surely failing to insert into a column should be 
> an error not success with info (an example of the latter is say an 
> insert which worked but truncated your data). What ODBC Driver manager 
> and driver versions are you using - you can find these from the 
> Administrative tools, data sources or in windows 7 by searching for 
> data sources in the control panel top right.
>
> Martin
>

When I run your code with a different driver to MS SQL Server it works 
as I'd expect:

use DBI;
use strict;
use warnings;

my $h = DBI->connect('dbi:ODBC:xx', 'xx', 'xx);

eval {$h->do(q/drop table feeds/);};
eval {$h->do(q/drop procedure api_add_feed/);};

my $table=<<'EOT';
CREATE TABLE feeds
(
     id             INT IDENTITY PRIMARY KEY,
     name           VARCHAR(400)  NOT NULL,
     descr          VARCHAR(4000) NOT NULL,
     url            VARCHAR(800)  NOT NULL,
     last_fetch     DATETIME,
     min_interval   INT,
     next_fetch     DATETIME,
     enabled        CHAR(1)       NOT NULL DEFAULT 'N',
     creator        VARCHAR(100),
     create_date    DATETIME      NOT NULL,
     lastup         DATETIME      NOT NULL,

     CONSTRAINT feed_url_uniq  UNIQUE (url),
     CONSTRAINT feed_name_uniq UNIQUE (name)
)
EOT

$h->do($table);

my $proc=<<'EOT';
CREATE PROCEDURE api_add_feed (@message        VARCHAR(2000) OUTPUT,
                                @new_id         INT           OUTPUT,
                                @name           VARCHAR(400),
                                @descr          VARCHAR(4000),
                                @url            VARCHAR(400),
                                @last_fetch     DATETIME,
                                @min_interval   INT,
                                @next_fetch     DATETIME,
                                @enabled        VARCHAR(1),
                                @creator        VARCHAR(50),
                                @create_date    DATETIME
                               )
AS
     DECLARE @proc VARCHAR(50), @err INT, @loc INT, @ctxt VARCHAR(100), 
@retval INT
     SELECT @proc='add_feed', @err=0, @retval=0, @message='No status yet.'

     INSERT INTO feeds
         (name, descr, url, last_fetch, min_interval, next_fetch, enabled,
          creator, create_date, lastup)
     VALUES
         (@name, @descr, @url, @last_fetch, @min_interval, @next_fetch, 
@enabled,
          @creator, @create_date, GETDATE())

     SELECT @err=@@ERROR, @loc=1, @ctxt='during insert into [feeds]', 
@new_id=SCOPE_IDENTITY()

     IF @err = 0
     BEGIN
         SET @retval = 0
         SET @message = 'Success. New feed id is ' + convert(varchar(6), 
@new_id) + '.'
     END
     ELSE
     BEGIN
         SET @message = 'Error in ' + @proc
                      + ' at '   + CONVERT(varchar(6), @loc)
                      + ' ('
                      + 'num '   + CONVERT(varchar(6), @err)
                      + ' / '
                      + 'context ' + @ctxt
                      + ')'
         SET @new_id =  0
         SET @retval = -1
     END

     RETURN @retval
EOT

$h->do($proc);

my $sth = $h->prepare('{? = call api_add_feed(?,?,?,?,?,?,?,?,?,?,?)}');
#$sth->trace($sth->parse_trace_flags('SQL|odbcconnection'), 
'trace-cxn.out');
#$sth->trace($sth->parse_trace_flags('4|odbcunicode'),      
'trace-cxn.out');

my ($retval, $message, $new_id);

$sth->bind_param_inout( 1, \$retval,   16, DBI::SQL_INTEGER);
$sth->bind_param_inout( 2, \$message, 400, DBI::SQL_VARCHAR);
$sth->bind_param_inout( 3, \$new_id,   16, DBI::SQL_INTEGER);
$sth->bind_param      ( 4, 'Some name',    DBI::SQL_VARCHAR);
$sth->bind_param      ( 5, 'Some desc',    DBI::SQL_VARCHAR);
$sth->bind_param      ( 6, 'Some url',     DBI::SQL_VARCHAR);
$sth->bind_param      ( 7, undef,          DBI::SQL_TIMESTAMP);
$sth->bind_param      ( 8, 3600,           DBI::SQL_INTEGER);
$sth->bind_param      ( 9, undef,          DBI::SQL_TIMESTAMP);
$sth->bind_param      (10, undef,          DBI::SQL_VARCHAR);  # Bad 
argument
$sth->bind_param      (11, 'Some user',    DBI::SQL_VARCHAR);
$sth->bind_param      (12, '2010-10-15 20:39:33',    DBI::SQL_TIMESTAMP);

my $exec_retval;
eval
{
     $exec_retval = $sth->execute;
};
if ($@)
{
     print qq{\$@ is "$@"\n----------------\n};
}

print "Execute() returned $exec_retval.\n";
print 'errstr is"', $sth->errstr, '"', "\n";

martin@bragi:~/svn/dbd-odbc/trunk/rt_data$ perl success_with_info.pl
DBD::ODBC::st execute failed: [unixODBC][Easysoft][SQL Server 
Driver][SQL Server
]Cannot insert the value NULL into column 'enabled', table 
'master.dbo.feeds'; c
olumn does not allow nulls. INSERT fails. (SQL-23000) [state was 23000 
now 01000
]
[unixODBC][Easysoft][SQL Server Driver][SQL Server]The statement has 
been termin
ated. (SQL-01000) at success_with_info.pl line 103.
Use of uninitialized value $exec_retval in concatenation (.) or string 
at succes
s_with_info.pl line 110.
Execute() returned .
errstr is"[unixODBC][Easysoft][SQL Server Driver][SQL Server]Cannot 
insert the v
alue NULL into column 'enabled', table 'master.dbo.feeds'; column does 
not allow
  nulls. INSERT fails. (SQL-23000) [state was 23000 now 01000]
[unixODBC][Easysoft][SQL Server Driver][SQL Server]The statement has 
been termin
ated. (SQL-01000)"
martin@bragi:~/svn/dbd-odbc/trunk/rt_data$

Which as far as I'm concerned is more evidence that your driver is 
broken. Please send me the driver name, version etc you are using. At 
the very least I may add a note that it is broken as there is little I 
might be able to do to work around this.

Martin
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