php - 如何计算从数据库表中检索到的包含 PHP 中特定值的逗号分隔数组

Question

我有一个像这样的 MySQL 表；

╔════╦═══════════════════════╗
║ id ║ comma_separated_stuff ║
╠════╬═══════════════════════╣
║  1 ║ 1, 2, 3, 4, 5         ║
║  2 ║ 1, 2, 5               ║
║  3 ║ 3, 7                  ║
║  4 ║ 4, 8                  ║
╚════╩═══════════════════════╝

我设法将每一行放入数组中，如数组[0]、数组[1]、数组[2]和数组[3]。问题是如何计算“有多少个逗号分隔数组包含 - 例如 - '5'？”

Answer 1

<?php
//how many of the comma-separated-arrays include for example '5'
$array = array(
'1, 2, 3, 4, 5',
'1, 2, 5',
'3, 7',
'4, 8',
);

$n = 5;
$sum = 0;
//Split the strings to arrays of numbers
foreach($array as $value)
{
    $data = explode(', ', $value);
    if (in_array($n, $data))
    {
        ++$sum;
    }
}

//prints 2
print $sum;