Relevant code:

 27     my $sth1 = $dbh->prepare ( $q1 );
 28     my $sth2 = $dbh->prepare ( $q2 );
 29
 30     print "INFO: If we got this far, we were able to create two \
statement handles.\n";
 31
 32     $sth1->execute or
 33       die ( "FATAL: Unable to execute q1: " . $sth1->errstr );
 34     $sth2->execute or
 35       die ( "FATAL: Unable to execute q2: " . $sth1->errstr );
[download]

INFO: If we got this far, we were able to create two statement handles
+.
DBD::ODBC::st execute failed: [FreeTDS][SQL Server]Invalid cursor stat
+e (SQL-24000) at two_handles.pl line 34.
FATAL: Unable to execute q2: [FreeTDS][SQL Server]Invalid cursor state
+ (SQL-24000) at two_handles.pl line 34.
Issuing rollback() due to DESTROY without explicit disconnect() of DBD
+::ODBC::db handle Driver=FreeTDS;ServerName=SqlServer;Database=FOOBAR
+ at two_handles.pl line 34.
[download]

Yeah, OK -- it looks like it's not DBD::ODBC.

The FreeTDS file freetds/src/tds/mem.c has a routine tds_alloc_lookup_sqlstate(TDSSOCKET * tds, int msgno) with a switch statement that appears to map a couple of errors to 24000; the first one is SQLS_ENTRY(16999, "24000"); /* Invalid cursor state */.

In the file freetds/src/odbc/error.c I see a line that appears to report an ODBC error of 24000 with the same text: ODBCERR("24000", "Invalid cursor state"),

So I've ansered my own question.

Alex / talexb / Toronto

Thanks PJ. We owe you so much. Groklaw -- RIP -- 2003 to 2013.

So it turns out I'm a goof (this is not surprising), and after posting here, ruminating, and digging through the FreeTDS code, my brain proposed another solution. If I can't have multiple statement handles for a single database handle, can I have multiple database handles, each with its own statement handle? I should try that, right? The solution couldn't be that obvious, right? RIGHT?

Good grief. I just tried it, and it works. I just created two $dbh guys, each with their own $sth; they each called my good friend fetchrow_hashref, and it all went swimmingly.

I understand this is called Rubber Duck Debugging. Now it's time for some Scotch to celebrate. You goofball.

Alex / talexb / Toronto

Thanks PJ. We owe you so much. Groklaw -- RIP -- 2003 to 2013.