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I am trying to insert a large object in a PostgreSQL database, but am having difficulties finding a graceful way to do this. Note that the included code has been simplified to avoid distractions--I am well aware that I should be addressing possible errors.

System information:

  • perl, version 5.005_03
  • Linux 2.2.14 i686
  • Postgres: 6.5.3
  • DBI: 1.1.3
  • DBD Pg: 0.93

I have created a table with one field, data, which is of type OID. Next I attempt to insert by more or less copying the code on page 153 of 'Programming the Perl DBI':

my $sth = $dbh->prepare("insert into foo(data) values (?);"); $sth->bind_param(1, $value, SQL_LONGVARBINARY); $sth->execute();
I receive a warning that binding the value isn't permitted:
SQL type 1075548612 for 'rc' is not fully supported, bound as VARCHAR +instead at ./1.0 line 122.
Whereupon it fails with a pg_atoi error.

I can insert by writing $value to a file and using the (presumably Postgres-specific) function lo_import:

$dbh->prepare("insert into foo(data) values (lo_import('/tmp/lame'));")
I'm not pleased with this solution because it requires the creation of a temporary file and it seems to undermine the use of DBI to use a database-specific insert.

I imagine some of the problem has to do with the unusual way Postgres deals with large objects. I expected that the Pg DBD would compensate for that, perhaps using lo_import, but accepting the format shown earlier.

The fact that I can't seem to find any documentation mentioning this problem (which I imagine must have occurred before) makes me feel as if I've completely failed to grasp something simple (or that Pg's documentation-dearth is contagious, affecting anything that touches Postgres). Is there a better way to insert a large object in Postgres using DBI? Thanks in advance.


In reply to Difficulty inserting a large object using DBD::Pg by kudra

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