Note that for some reason the length of fields is 3 times the actual value if you are using UTF8 encoding.. So a varchar(10) field returns 30 here. This renders this function almost useless.
mysql_field_len
(PHP 4, PHP 5)
mysql_field_len — Returns the length of the specified field
Увага
This extension is deprecated as of PHP 5.5.0, and will be removed in the future. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide and related FAQ for more information. Alternatives to this function include:
- mysqli_fetch_field_direct() [length]
- PDOStatement::getColumnMeta() [len]
Опис
int mysql_field_len
( resource
$result
, int $field_offset
)mysql_field_len() returns the length of the specified field.
Параметри
-
result -
The result resource that is being evaluated. This result comes from a call to mysql_query().
-
field_offset -
The numerical field offset. The
field_offsetstarts at 0. Iffield_offsetdoes not exist, an error of levelE_WARNINGis also issued.
Значення, що повертаються
The length of the specified field index on success або FALSE в разі помилки.
Приклади
Приклад #1 mysql_field_len() example
<?php
$result = mysql_query("SELECT id,email FROM people WHERE id = '42'");
if (!$result) {
echo 'Could not run query: ' . mysql_error();
exit;
}
// Will get the length of the id field as specified in the database
// schema.
$length = mysql_field_len($result, 0);
echo $length;
?>
Примітки
Зауваження:
Для зворотньої сумісності, можна використовувати наступний застарівший псевдонім: mysql_fieldlen()
Прогляньте Також
- mysql_fetch_lengths() - Get the length of each output in a result
- strlen() - Повертає число байтів в рядку
add a note
User Contributed Notes 2 notes
rvwoens at gmail dot com ¶
12 years ago
adam_nospam_hunger at yahoo dot com ¶
20 years ago
For a mysql type DECIMAL(8,4), the length is returned as 10 (M+2 as per documentation).
