Basic usage
示例 #1 DBA example
<?php
$id = dba_open("/tmp/test.db", "n", "db2");
if (!$id) {
echo "dba_open failed\n";
exit;
}
dba_replace("key", "This is an example!", $id);
if (dba_exists("key", $id)) {
echo dba_fetch("key", $id);
dba_delete("key", $id);
}
dba_close($id);
?>
DBA is binary safe and does not have any arbitrary limits. However, it inherits all limits set by the underlying database implementation.
All file-based databases must provide a way of setting the file mode of a new created database, if that is possible at all. The file mode is commonly passed as the fourth argument to dba_open() or dba_popen().
You can access all entries of a database in a linear way by using the dba_firstkey() and dba_nextkey() functions. You may not change the database while traversing it.
示例 #2 Traversing a database
<?php
// ...open database...
$key = dba_firstkey($id);
while ($key !== false) {
if (true) { // remember the key to perform some action later
$handle_later[] = $key;
}
$key = dba_nextkey($id);
}
foreach ($handle_later as $val) {
dba_delete($val, $id);
}
?>