Re: How to detect if a table exists, with DBD::DBM

[David McMath]

On 04/03/2011 06:18 AM, Jens Rehsack wrote:

On 04/01/11 17:15, David McMath wrote:

Dear List,

Hi David,

I quick reply now without taking a look into the details of the
implementation to prevent that I forget you (I'm currently busy
with other tasks ...).

...

I've tried "$dbh->func('list_tables')" but that just lists all the files
in the directory. I'd rather not use that because I'd rather not have to
remember how the particular DBM handles extensions.

This shouldn't happen with a proper configured DBD::DBM session. If I
forgot to dig deeper here within next 4 business days, please feel free
to remind me.

You should include the version numbers of DBI and SQL::Statement
you use in your environment and they should better match the latest
released versions ;)
Further, you should add the OS(s) you're using (just to be sure).

  https://rt.cpan.org/Public/Bug/Display.html?id=67223



Thanks again for your help,

dave

--

[mcdave@epgy-dsk-999 ticketServer]$ uname -a

[mcdave@epgy-dsk-999 ticketServer]$ perl gdb_test_list.pl
Version information:

  DBD::File              0.40 using IO::File (1.14)
    DBI::DBD::SqlEngine  0.03 using SQL::Statement 1.33
DBI                      1.616
OS                       linux (2.6.18-128.1.10.el5)
Perl                     5.008008 (x86_64-linux-thread-multi)
List of tables:

 (tid TEXT PRIMARY KEY
 , user_id INTEGER
 , started DATE
 , status_f VARCHAR(16)
 , value_f VARCHAR(255)
 )
"] at gdb_test_list.pl line 19.
Can't find column definitions! at gdb_test_list.pl line 18.

Thanks for your time. Including version numbers is always good advice. When I wrote the original, DBI was something very old and DBD::DBM was v0.03. After updating, I understand that list_tables should work. The attached script almost does the right thing except for a bug in SqlEngine (?). I described that at I don't think "CREATE TABLE IF NOT EXISTS" parses, even after I updated everything I could think of. The attached script gives the output below. But the list_tables trick is good enough for me. Linux epgy-dsk-999.Stanford.EDU 2.6.18-164.11.1.el5 #1 SMP Wed Jan 6 13:26:04 EST 2010 x86_64 x86_64 x86_64 GNU/Linux Use of uninitialized value in concatenation (.) or string at /usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi/DBD/DBM.pm line 178. Use of uninitialized value in concatenation (.) or string at /usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi/DBD/DBM.pm line 185. DBD::DBM 0.06 using SDBM_File () + MLDBM () + MLDBM::Serializer::Storable Can't use string ("tickets") as an ARRAY ref while "strict refs" in use at /usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi/DBI/DBD/SqlEngine.pm line 688. Can't find column definitions! at /usr/lib/perl5/site_perl/5.8.8/SQL/Statement.pm line 88 DBD::DBM::db do failed: Can't find column definitions! [for Statement "CREATE TABLE IF NOT EXISTS tickets

gdb_test_list.pl
Description: Perl program