in reply to error catching

I'm not sure $! is populated there. $! is frequently used to print errors from syscalls and the like (see perlvar). What you should be using is "or die $dbh->errstr" in my opinion. However, mostly people leave the DBI on it's default settings, which carp() errors before you ever get to the "or" part of your statement. Therefore, die()ing may be enough anyway.

-Paul

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Re^2: error catching
by Joost (Canon) on Dec 20, 2006 at 00:51 UTC
    However, mostly people leave the DBI on it's default settings, which carp() errors before you ever get to the "or" part of your statement.
    While I don't know what people normally do, the DBI default is for some unexplicable reason to not do that: (from the docs):
    "RaiseError" (boolean, inherited)

    The "RaiseError" attribute can be used to force errors to raise exceptions rather than simply return error codes in the normal way. It is "off" by default. -snip-

    Update: just to be clear: the parent node's comments about $! and $dbi->errstr are correct, it's just that the default DBI setting is to use those, and not throw exceptions. If you want to automatically get an exception on a database/SQL error (and I suggest you should), you need to use the RaiseError option on the DBI->connect call.

    update2: jettero is correct in his correction, but we both seem to agree that you should use RaiseError to catch any further errors. The chances of anything unexpected going wrong later without notice are a lot higher if you don't.

      While I don't know what people normally do, the DBI default is for some unexplicable reason to not do that: (from the docs):

      False. I was reading just above where you were reading.

      By default, "DBI->connect" sets "PrintError" "on"

      I agree that you still have to die() if your $sth fails, which I thought I had implied, but it will (by default) at least print the error on its own. The RaiseError is different and actually croak()s instead of just carp()ing.

      Update, because it happens to be on my other monitor anyway, here's the relevant source [the comments are mine]:

      Carp::croak($msg) if $attr->{RaiseError}; # not default Carp::carp ($msg) if $attr->{PrintError}; # default

      -Paul

      RaiseError doesn't work for the initial ->connect statement. You need to check that one manually.

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        Yes, it does. Since 0.91.