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(PHP 4, PHP 5)
mysql_field_len — 返回指定字段的长度
本扩展自 PHP 5.5.0 起已废弃,并在自 PHP 7.0.0 开始被移除。应使用 MySQLi 或 PDO_MySQL 扩展来替换之。参见 MySQL:选择 API 指南来获取更多信息。用以替代本函数的有:
result
resource 型的结果集。此结果集来自对 mysql_query() 的调用。
field_offset
数值型字段偏移量。
field_offset
从 0
开始。如果
field_offset
不存在,则会发出一个
E_WARNING
级别的错误
The length of the specified field index on success 或者在失败时返回 false
.
示例 #1 mysql_field_len() 示例
<?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;
?>
注意:
为了向下兼容,可以使用下列已废弃的别名: mysql_fieldlen()