dbmopen> <dbminsert
Last updated: Mon, 28 Dec 2009

dbmnextkey

(PHP 4)

dbmnextkey —

Descrição

string dbmnextkey ( resource $dbm_identifier , string $key )

Returns the next key after key .

Parâmetros

dbm_identifier

O identificador da conexão DBM, retornado por dbmopen().

key

The previous key

Valor Retornado

The next key if possible

Exemplos

By calling dbmfirstkey() followed by successive calls to dbmnextkey() it is possible to visit every key/value pair in the dbm database. For example:

Example#1 Visiting every key/value pair in a DBM database

<?php

$key 
dbmfirstkey($dbm_id);
while (
$key) {
    echo 
"$key = " dbmfetch($dbm_id$key) . "\n";
    
$key dbmnextkey($dbm_id$key);
}

?>

Veja também



User Contributed Notes
dbmnextkey
fischer at schlund dot de
19-Mar-2001 03:08
When you have a key "0" or so in your DB, then the example don't works, because "while ($key)" will return false for 0 ...
I had good experiences with "while (strlen($key)>0)" as condition ... because when we have the last key false is returned and false evaluates to "nothing" ...
fred at ontosys dot com
12-Oct-2000 03:41
dbmnext() seems to lose the thread if the program deletes keys as it walks through all rows.  I imagine that something similar happens with inserts.  One way around this is to make two passes:  one to collect the keys and one to manipulate the rows.  For example:

<?php
$old_keys
= array();
for (
$key = dbmfirstkey($db); $key; $key = dbmnextkey($db, $key)) {
 
$old_keys[] = $key;
}
while (list(
$_, $key) = each($old_keys)) {
   
dbmdelete($db, $key);
}
?>

dbmopen> <dbminsert
Last updated: Mon, 28 Dec 2009