(PHP 4, PHP 5, PHP 7, PHP 8)
pg_fetch_object — Lee una fila de resultado PostgreSQL en un objeto
$result,$row = null,$class = "stdClass",$constructor_args = []pg_fetch_object() devuelve un objeto con sus propiedades que corresponden a los nombres de los campos de la fila. La función puede instanciar opcionalmente un objeto de una clase específica y pasar los argumentos al constructor de dicha clase.
Nota: Esta función define campos NULOS al valor
nullde PHP.
En cuanto a velocidad, la función es idéntica a pg_fetch_array() y es casi tan rápida como pg_fetch_row() (la diferencia es insignificante).
resultAn PgSql\Result instance, returned by pg_query(), pg_query_params() or pg_execute()(among others).
row
Número de la fila a recuperar. Las filas se numeran comenzando por 0. Si el argumento se omite o es null, se recupera la siguiente fila.
classEl nombre de la clase a instanciar, fija las propiedades de esta y sus valores de retorno. Si no se especifica nada, se devuelve un objeto de tipo stdClass.
constructor_args
Parámetro opcional de tipo array para pasar argumentos al constructor de la clase class.
Un objeto de tipo object con los atributos para cada campo en el conjunto de resultados. Los valores null de la base de datos se devuelven como null.
false se devuelve si row excede el número de filas en el conjunto de resultados, no hay más filas disponibles o cualquier otro error.
Se lanza una ValueError cuando el argumento constructor_args no está vacío y la clase no tiene constructor.
| Versión | Descripción |
|---|---|
| 8.3.0 |
Ahora lanza una excepción ValueError cuando el argumento constructor_args no está vacío y la clase no tiene constructor; anteriormente, se lanzaba una excepción Exception.
|
| 8.1.0 |
The result parameter expects an PgSql\Result
instance now; previously, a recurso was expected.
|
Ejemplo #1 Ejemplo con pg_fetch_object()
<?php
$database = 'store';
$db_conn = pg_connect("host=localhost port=5432 dbname=$database");
if (!$db_conn) {
echo "La conexión a la base $database ha fallado\n";
exit;
}
$qu = pg_query($db_conn, "SELECT * FROM libros ORDER BY autor");
while ($data = pg_fetch_object($qu)) {
echo $data->autor . " (";
echo $data->anio . "): ";
echo $data->titulo . "<br />";
}
pg_free_result($qu);
pg_close($db_conn);
?>
PostgreSQL boolean true becomes string "t"
PostgreSQL boolean false becomes string "f"
This is ambiguous, and leads to code duplication. I wonder why aren't the types correctly typed when fetching values. We could at least have an optional parameter to enable that.If you're wanting to use objects for your results, but are put off because you can't seem to apply a function to each field of the result (like stripslashes for example), try this code:
<?php
// Code to connect, do query etc etc...
$row = pg_fetch_object($result);
$vars = get_object_vars($row);
foreach ( $vars as $key => $var )
{
$row->{$key} = stripslashes($var);
}
?>I noticed that many people use FOR loops to extract query data. This is the method I use to extract data.
<?php
@$members = pg_query($db_conn, 'SELECT id,name FROM boards.members ORDER BY name;');
if ($members AND pg_num_rows($members)) {
while ($member = pg_fetch_object($members)) {
echo $member->name.' ('.$member->id.')';
}
}
?>
If an error occurs (or nothing is returned) in the above code nothing will output. An ELSE clause can be added to the IF to handle query errors (or nothing being returned). Or a seperate check can be performed for the event that nothing is returned by using an ELSEIF clause.
I like this method because it doesn't use any temporary counter variables.The result_type arg is either invalid or incorrectly documented, since the "result_type is optional..." paragraph is copied verbatim from pg_fetch_array, and the PGSQL_NUM option is in conflict with the preceding paragraph's, "you can only access the data by the field names, and not by their
offsets."When you retrieve the contents of a "timestamp with timezone" field, this will set the environment's timezone variables. Therefore, this is dangerous:
$s=$row->mydatefield;
$unixtimestamp=postgresqltimestamp2unix($s);
echo date("Y-m-d H:i:s",$unixtimestamp);
Here, postgresqltimestamp2unix is a function that converts the postgresql timestamp to Unix. The retrieval of the field data in the first line of the example above will influence the timezone used in date() in the third line.This isn't all that useful. If you do, for example, foreach($row as $field) then you still get every value twice!
You can do something like this, though:
foreach ($line as $key => $cell){
if (! is_numeric($key)){
echo "<td>$key $cell</td>";
}
}
is is_numeric strict enough?Getting db results as object.
<?php
$qry = pg_query("SELECT * FROM users");
$rows = array();
while ($fch = pg_fetch_object($qry)) {
$rows[] = $fch;
}
// or
$rows = array_map(function($a){
return (object) $a;
}, (array) pg_fetch_all($qry));
?>Something I have learned to use:
$result=$pg_query (...);
$num = pg_numrows($result);
for($count=0;$count < $num && $data=pg_fetch_object($result,$count);$count++)
{
printf("<tr>\n");
printf(" <td>%s</td>\n",$data->foo);
printf(" <td>%s</td>\n",$data->bar);
printf("</tr>\n");
}