Perl DBI / FreeTDS / SQL-Server：如何插入/更新 BLOB varbinary(max) 数据？

Question

I am trying to insert binary data into a VARBINARY(max) column on an Microsoft SQL-Server 2014 via DBI and freeTDS in Linux.

Following (simplified) code does not work:

$data = "foobar"; # real binary data gives same error
$dbh = <...valid db-handle ...>;
$sth = $dbh->prepare ("UPDATE table SET data=? WHERE id=?");
$sth->bind_param (1,$data,DBI::SQL_VARBINARY);
$sth->bind_param (2,$some_id);
$sth->execute or die ...

Results in:

ct_result(ct_dynamic(CS_PREPARE)) returned -205 at /usr/lib/x86_64-linux-gnu/perl5/5.28/DBD/Sybase.pm line 138.
DBD::Sybase::db prepare failed: Server message number=257 severity=16 state=3 line=1 server=SERVER text=Implicit conversion from data type varchar to varbinary(max) is not allowed. Use the CONVERT function to run this query. Server message number=8180 severity=16 state=1 line=1 server=...
Can't call method "bind_param" on an undefined value 

It seems like the bind_param call tails to encode the binary data correctly. The undefined value error seems to be a result of the failed bind execution. I tried various other column types for bind_param like SQL_LONGVARBINARY, SQL_BLOB ... but the error stays the same.

Answer 1

https://metacpan.org/pod/distribution/DBD-Sybase/dbd-sybase.pod#String-Data-Handling

DBD::Sybase supports CHAR/VARCHAR/BINARY/VARBINARY, limited to 255 characters in length up to version 12.0x. As of 12.5 these datatypes can be up to 16K in size - but supporting the larger sizes requires that Open Client 12.5 or later be used.

Sybase does not differentiate between CHAR and VARCHAR or BINARY and VARBINARY

It seems that DBD::Sybase ignores DBI::SQL_VARBINARY hint and sends the data as varchar .

Try:

UPDATE table SET data=CONVERT(VARBINARY(max), ?, 1) WHERE id=?

Also check syb_use_bin_0x setting.