CaptainDaddy has asked for the wisdom of the Perl Monks concerning the following question:

Recently I've had trouble putting files larger than a certain size (around 3kb) into a sql server. I've been using unixODBC, DBD:ODBC, and FreeTDS.
I've noticed that a similar issue was posted on CPAN as a bug for the latest DBC:ODBC, and didn't understand the fix that the poster found.
I recently switched from DBD:ODBC to DBD:Sybase, and after what I felt was an unnescessary use of CONVERT (see my thread 'dbd odbc sql big file blues') I could insert very large varbinaries.
However when I try to insert real files using this method I get a warning that there is an error converting characters and the files get stomped on. This seems odd to me since I use

binmode(FILE);
$fdata=read(FILE,$filelength);

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before I bind the data for insert. I'd like to use a solution with freeTDS for obvious reasons; it was suggested that I use the easysoft driver in the above mentioned thread and I will try that with dbd:odbc and post the results there, but this seems a problem separate from freeTDS. I'll be grateful for any help in this.

Replies are listed 'Best First'.
Re: dbd:Sybase bit scramble
by mje (Curate) on Mar 21, 2013 at 09:55 UTC

    Just a small correction to your reference to dbd odbc sql big file blues. I didn't (and I don't think anyone else did either) recommend you used the Easysoft SQL Server ODBC Driver I simply showed you that your code worked with that driver as part of my evidence that something (possibly freeTDS) was broken.

    Also, could you point me at this "similar issue was posted on CPAN as a bug for the latest DBC:ODBC".

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        FWIW I don't think the issue you hit and the one you point to are related. As you may have seen if you looked down the whole log for that bug I rejected it as not a DBD::ODBC but the reporter keeps coming back and reopening it.

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      Code

      #
$host='...';
$port='...';
$user = "...";
$pass = "...";
$dsn="dbi:Sybase;server=dbhDB;database=...;";
$dbh= DBI->connect("$dsn",$user,$pass) or die "can't connect";


$fileTableName="fileTable";
$cmd="SELECT 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='BASE T
+ABLE' AND TABLE_NAME='$fileTableName\'";
$fetchcmd= $dbh->prepare($cmd);
$fetchcmd->execute();
if(@row= $fetchcmd->fetchrow_array){
        print "the file table is there!!!\n";
}else {
        $createCmd=$dbh->prepare("create table $fileTableName (fileCol
+umn VARBINARY(MAX) not null)");
        $createCmd->execute() or die "can't  create table";
        $createCmd->finish();
}
$fetchcmd->finish();

$insertcmd= $dbh-> prepare("insert into $fileTableName (fileColumn) va
+lues (CONVERT(varbinary(max),?))");
open FILE,"<","./a.b" or die "file";
binmode(FILE);
$filelength = -s FILE;
read(FILE,$fcontents,$filelength);

print"did";
$insertcmd->bind_param(1,$fcontents,DBI::SQL_VARBINARY);
$insertcmd->execute() or print" not ";
$insertcmd->finish();
$sz=length($insert);
print " succeed. size: $sz\n";
close(FILE);

$dbh->disconnect;

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      results

      >perl sybasefiletrial.pl
the file table is there!!!
DBD::Sybase::st execute failed: OpenClient message: LAYER = (0) ORIGIN
+ = (0) SEVERITY = (9) NUMBER = (98)
Server dbhDB, database
Message String: Error converting characters into server's character se
+t. Some character(s) could not be converted
did succeed. size: 0

      [download]
      I probably am missing something obvious here; help will be apprecieated.
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