You can approach time in databases many different ways..

But if you're just starting out, and just want to conquer a simple problem - like how to delete rows 5 minutes old, then I suggest a simple way, and it's compatible with every database you'll ever come across:

  CREATE TABLE mytable
  (
      person VARCHAR(20),
      lasttime INTEGER
  );

[download]

When you want to insert a row with the current time, run a query like this:

  my $sql = "INSERT INTO mytable (person,lasttime) VALUES ?, ?";
  my $sth = $dbh->prepare( $sql );
  if ( $sth && $sth->prepare( $person, time() ) )
  {
      ; # success
  }
  else
  {
      die( "DB Error " . $dbh->errstr . "\n" );
  }

[download]

When you want to delete a row just run a query like:

  my $timenow = time();
  my $fiveminutes = 5 * 60; # 60 seconds times five
  my $timethen = $timenow - $fiveminutes;

  my $sql = "DELETE FROM mytable WHERE lasttime < ?";
  my $sth = $dbh->prepare( $sql );
  if ( $sth && $sth->execute( $timethen ) )
  {
      ; # success
  }
  else
  {
      die( "DB Error " . $dbh->errstr . "\n" );
  }

[download]

In reply to Re: 5 minutes of time by monarch
in thread 5 minutes of time by Anonymous Monk

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