Your code will remove all of the entries from the
database (unless there is only one entry in @test),
because for each element of @test it removes all
the entries that are not equal to that element. You
want to do the opposite: remove all the elements
that are not represented in @test (i.e., not equal
to _any_ of the entries in @test). So, you're looping
over the wrong thing. Instead of looping over the
list of things you don't want to delete, you want to
loop over all the entries in the database and for
each one you want to decide whether to delete it
or not.
# This is untested. Test on sample data that
# doesn't matter before using on live data.
my %represented = map{$_=>1} @test;
my $sth = $dbh->prepare("SELECT Name FROM tnt");
my $del=$dbh->prepare("DELETE FROM tnt WHERE Name=?");
$sth->execute();
while (my $line = $sth->fetchrow_hashref()) {
if (not $represented{$$line{Name}}) {
$del->execute($$line{Name});
}
}
Update: minor optimization (prepare $del once
outside the loop, instead of n times inside).
$;=sub{$/};@;=map{my($a,$b)=($_,$;);$;=sub{$a.$b->()}}
split//,".rekcah lreP rehtona tsuJ";$\=$ ;->();print$/
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|