Re: Prooblem writing empty strings to mySQL db

[prev] [thread] [next] [Date index for 2004/12/22]

Hi Dave,

I am using oracle but this should also apply for sybase.

Empty string '_' is logically equivalent to NULL.

After executing

  SET value = ''  WHERE mac='blah' AND name='foo'

The value of field value in this record should (this is what happends in 
oracle too) be NULL.

Means instead of setting value to '_', set it to undef

my $setting = My::Setting->retrieve(mac => "blah", name => "foo");
$setting->set(value => undef);
$setting->update();

Class::DBI will generate:

SET value = NULL  WHERE mac='blah' AND name='foo'

hope this helps
adam



cdbi@xxxxxxxxxx.xxx wrote:

>Hi, I'm new to Class::DBI and I've done some searching and could not figure this problem out.  I'm trying to write an empty string to a column in my database, but I get a SQL syntax error instead.
>
>Without giving all the code, I'm essentially doing this:
>
>my $setting = My::Setting->retrieve(mac => "blah", name => "foo");
>$setting->set(value => "");
>$setting->update();
>
>Then I run the code with DBI_TRACE=2, so I see the SQL, and it looks like:
>
>SET value =
>WHERE mac='blah' AND name='foo'
>
>And this generates an error.  Whereas this SQL would work fine...
>
>SET value = ''
>WHERE mac='blah' AND name='foo'
>
>So how do I get Class::DBI to do the latter?
>
>Thanks for any help,
>
>-Dave
>
>  
>