pg_fetch_object

(PHP 4, PHP 5, PHP 7, PHP 8)

pg_fetch_object — 获取一行作为对象

说明

pg_fetch_object(
    PgSql\Result $result,
    ?int $row = null,
    string $class = "stdClass",
    array $constructor_args = []
): object|false

pg_fetch_object() 返回对象，该对象的属性对应于获取的行的字段名称。它可以选择实例化特定类的对象，并将参数传递给该类的构造方法。

注意: 此函数将 NULL 字段设置为 PHP null 值。

在速度方面，该函数与 pg_fetch_array() 相同，并且几乎与 pg_fetch_row() 一样快（差别不大）。

参数

result: PgSql\Result 实例，由 pg_query()、pg_query_params() 或者 pg_execute()（等）返回。
row: 要获取的结果中的行号。行从 0 向上编号。如果省略或为 null，则获取下一行。
class: 要实例化、设置属性并返回的类的名称。如果未指定，则返回 stdClass 对象。
constructor_args: 要传递给 class 对象的构造方法的可选参数 array。

返回值

结果中的每个字段名称都有在 object 中对应的属性。数据库 NULL 值作为 null 返回。

如果 row 超过集合中的行数、没有更多行或任何其他错误，则返回 false。

错误／异常

当 constructor_args 非空而类没有构造方法时，会抛出 ValueError。

更新日志

版本	说明
8.3.0	当 `constructor_args` 非空而类没有构造方法时，现在会抛出 ValueError 异常；之前抛出 Exception。
8.1.0	现在 `result` 参数接受 PgSql\Result 实例，之前接受 resource。

示例

示例 #1 pg_fetch_object() 示例

<?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);

?>

参见

pg_query() - 执行查询
pg_fetch_array() - 获取一行作为数组
pg_fetch_assoc() - 获取一行作为关联数组
pg_fetch_row() - 提取一行作为枚举数组
pg_fetch_result() - 从结果实例返回值

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＋添加备注

用户贡献的备注 8 notes

down

ekevu at yahoo dot com ¶

17 years ago

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.

down

oracle dot shinoda at gmail dot com ¶

20 years ago

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);
}

?>

down

robeddielee at hotmail dot com ¶

19 years ago

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.

down

-1

inbox at bucksvsbytes dot com ¶

22 years ago

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."

down

-2

Lars at dybdahl dot dk ¶

21 years ago

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.

down

-2

ian at eiloart dot com ¶

22 years ago

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?

down

-2

qeremy [atta] gmail [dotta] com ¶

12 years ago

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));

?>

down

-4

michiel at minas-2 dot demon dot nl ¶

20 years ago

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");
}

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