pg_fetch_object
(PHP 4, PHP 5)
pg_fetch_object — Fetch a row as an object
Description
$result
[, int $row
[, int $result_type = PGSQL_ASSOC
]] )$result
[, int $row
[, string $class_name
[, array $params
]]] )pg_fetch_object() returns an object with properties that correspond to the fetched row's field names. It can optionally instantiate an object of a specific class, and pass parameters to that class's constructor.
Note: This function sets NULL fields to the PHP
NULLvalue.
Speed-wise, the function is identical to pg_fetch_array(), and almost as fast as pg_fetch_row() (the difference is insignificant).
Parameters
-
result -
PostgreSQL query result resource, returned by pg_query(), pg_query_params() or pg_execute() (among others).
-
row -
Row number in result to fetch. Rows are numbered from 0 upwards. If omitted or
NULL, the next row is fetched. -
result_type -
Ignored and deprecated.
-
class_name -
The name of the class to instantiate, set the properties of and return. If not specified, a stdClass object is returned.
-
params -
An optional array of parameters to pass to the constructor for
class_nameobjects.
Return Values
An object with one attribute for each field
name in the result. Database NULL
values are returned as NULL.
FALSE is returned if row exceeds the number
of rows in the set, there are no more rows, or on any other error.
Changelog
| Version | Description |
|---|---|
| 5.0.0 |
class_name and params
were added. The old form with result_type
still exists for backwards compatibility.
|
| 4.3.0 |
result_type default changed from
PGSQL_BOTH to PGSQL_ASSOC,
since the numeric index was illegal.
|
| 4.1.0 |
The parameter row became optional.
|
Examples
Example #1 pg_fetch_object() example
<?php
$database = "store";
$db_conn = pg_connect("host=localhost port=5432 dbname=$database");
if (!$db_conn) {
echo "Failed connecting to postgres database $database\n";
exit;
}
$qu = pg_query($db_conn, "SELECT * FROM books ORDER BY author");
while ($data = pg_fetch_object($qu)) {
echo $data->author . " (";
echo $data->year . "): ";
echo $data->title . "<br />";
}
pg_free_result($qu);
pg_close($db_conn);
?>
See Also
- pg_query() - Execute a query
- pg_fetch_array() - Fetch a row as an array
- pg_fetch_assoc() - Fetch a row as an associative array
- pg_fetch_row() - Get a row as an enumerated array
- pg_fetch_result() - Returns values from a result resource
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Расширения для работы с базами данных
- Расширения для работы с базами данных отдельных производителей
- PostgreSQL
- pg_affected_rows
- pg_cancel_query
- pg_client_encoding
- pg_close
- pg_connect_poll
- pg_connect
- pg_connection_busy
- pg_connection_reset
- pg_connection_status
- pg_consume_input
- pg_convert
- pg_copy_from
- pg_copy_to
- pg_dbname
- pg_delete
- pg_end_copy
- pg_escape_bytea
- pg_escape_identifier
- pg_escape_literal
- pg_escape_string
- pg_execute
- pg_fetch_all_columns
- pg_fetch_all
- pg_fetch_array
- pg_fetch_assoc
- pg_fetch_object
- pg_fetch_result
- pg_fetch_row
- pg_field_is_null
- pg_field_name
- pg_field_num
- pg_field_prtlen
- pg_field_size
- pg_field_table
- pg_field_type_oid
- pg_field_type
- pg_flush
- pg_free_result
- pg_get_notify
- pg_get_pid
- pg_get_result
- pg_host
- pg_insert
- pg_last_error
- pg_last_notice
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- pg_socket
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- pg_tty
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- pg_update
- pg_version
Коментарии
The result_type arg is either invalid or incorrectly documented, since the "result_type is optional..." paragraph is copied verbatim from pg_fetch_array, and the PGSQL_NUM option is in conflict with the preceding paragraph's, "you can only access the data by the field names, and not by theiroffsets."
This isn't all that useful. If you do, for example, foreach($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?
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.
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");
}
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.
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.
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));
?>