MySQL条件

添加 WHERE 条款来办理你的登机手续 UPDATE 查询:

// I assume you mean you want to increment the current column by 1,
// but it's your table so change the SET values as needed
$updated = mysql_query('UPDATE table SET current = current + 1 WHERE id = ' . intval($row_id) . ' AND current < capacity');

mysql_affected_rows() 的 更新 查询:

if (mysql_affected_rows() > 0)
{
    // Success
}

select (current >= capacity) as exceeded from table