php - 使用 COUNT( * ) 返回 Mysql 结果

Question

我正在尝试从 mysql 返回计数。我的代码如下

$number_of_options_sql = tep_db_query("SELECT COUNT( * ) FROM 
(select sum(options_id) as total from products_attributes 
where products_id='".$products_id."' group by options_id) as total");
$number_of_options_result = tep_db_fetch_array($number_of_options_sql);

当我在 Phpmyadmin 中运行此查询时，它会在表标题处显示带有 COUNT(*) 的结果。我得到了正确的结果，查询对我有用，我只是无法在屏幕上打印出来。

我尝试通过以下方式返回值，但没有在屏幕上打印任何内容:

echo $number_of_options_result[COUNT( * )];
echo $number_of_options_result[total];

Answer 1

在 COUNT(*) 后使用 AS field_name

$number_of_options_sql = tep_db_query("SELECT COUNT(*) AS field_name FROM (select sum(options_id) as total from products_attributes where products_id='".$products_id."' group by options_id) as total");

打印:

echo $number_of_options_result['field_name'];

(将“field_name”替换为您选择的任何相关名称)