获取行并检查是否具有相同的值

Question

我对编码和尝试学习 PHP 和 MYSQL 非常陌生。我正在尝试做的是，将相同的 CustomerID 查询分组到同一个表中，同时进行回显。目前，我的代码回显了所有单独的查询。我有一张像

ID      CustomerID     DATE        Company
1           1       2018-11-19        A
2           1       2018-11-19        A
3           2       2018-11-19        B
4           3       2018-11-19        C
5           4       2018-11-19        D
6           4       2018-11-19        D

我的代码

$query = "SELECT `customers`.ID, `customers`.customerid, `customers`.date
        FROM `customers` WHERE month(DATE)= month(CURRENT_DATE()) AND YEAR(DATE) = YEAR(CURRENT_DATE());

$result = $mysqli->query($query);

while($resultquery = $result->fetch_array())

{
$queryresult[] = $resultquery;

}
if (!empty($queryresult)) {

foreach($queryresult as $queryresults)
{

$id = $queryresults['id'];
$customerid = $queryresults['customerid'];  
$date = $queryresults['date'];
?>

然后我回显它，结果是

Company Name: A
ID CustomerID DATE
1      1    2018-11-19

Company Name: A
ID CustomerID DATE
2      1    2018-11-19

Company Name: B
ID CustomerID DATE
3      2    2018-11-19

Company Name: C
ID CustomerID DATE
4      3    2018-11-19

<?php }} ?>

等等。

但我想要的是比较 customerID，如果有多个具有相同 id 的，则将它们作为一个组在表中回显。

Company Name: A
ID CustomerID DATE
1      1    2018-11-19
2      1    2018-11-19

Company Name: B
ID CustomerID DATE
3      2    2018-11-19

Company Name: C
ID CustomerID DATE
4      3    2018-11-19

我使用 GROUP_CONCAT 进行了一个 sql 查询，并使用 SEPARATOR '|') 对结果进行分组，它可以工作，但我认为它不是实现这一目标的最佳方法，所以请帮忙。谢谢

Answer 1

将您的数据映射到以 Company 为键的键值数组中（在查询中包括公司：

$query = "选择customers.ID，customers.customerid，customers.date，公司 FROM customers WHERE month(DATE)= month(CURRENT_DATE()) AND YEAR(DATE) = YEAR(CURRENT_DATE())";

$query = "SELECT `customers`.ID, `customers`.customerid, `customers`.date
        FROM `customers` WHERE month(DATE)= month(CURRENT_DATE()) AND YEAR(DATE) = YEAR(CURRENT_DATE());

然后使用键对项目进行分组来简化数据收集：

$result = $mysqli->query($query);
$queryresult = [];
while($resultquery = $result->fetch_array())

{
 $company = $resultquery['company'];
 if (array_key_exists($company,$queryresult){
   @$queryresult[$company] = [];
 }
 @$queryresult[$company][] = $resultquery;

}

然后您可以使用 foreach 呈现信息：

foreach($queryresult as $company => $items){
   // header by company
   echo "Company Name: $company \n";
   echo "ID CustomerID DATE\n";
   foreach($items as $item){
     // items in company
     echo "{$item['id']} {$item['customerid']} {$item['date']}\n"; 
  }

}