Php 不同于一个表，不同于另一个表的值

我不确定问这个问题的正确方法：我想从一个表中选择一个不同的值，然后从另一个表中获取值

$sql1 = mysql_query("SELECT DISTINCT County_ID FROM Customers ORDER BY County_ID ASC") or die(mysql_error());
while($row1 = mysql_fetch_array( $sql1 ))
{
    $sql2 = mysql_query("SELECT County_Value FROM Counties") or die(mysql_error());
    while($row2 = mysql_fetch_array( $sql2 ))
        {
            echo "Listed Counties : ".$row2['County_Value']." - id : ".$row1['County_ID']."<br>";
        }
}

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PS：我应该说，我想从customers表中获得一个列出的县列表，但这些县作为id存储在Countries表中，因此我只需要不同的Countrie_值ASC

可能类似于这样：-

SELECT CustomersSub.County_ID, County_Value 
FROM (SELECT DISTINCT County_ID FROM Customers) CustomersSub
INNER JOIN Counties 
ON Counties.County_ID = CustomersSub.County_ID 
ORDER BY County_Value ASC

编辑-或使用聚合函数并统计每个县的客户数：-

SELECT Counties.County_ID, County_Value, COUNT(Customers.County_ID) AS CustCountyCount
FROM Counties 
INNER JOIN Customers
ON Counties.County_ID = Customers.County_ID 
GROUP BY Counties.County_ID, County_Value
ORDER BY County_Value ASC

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请扩展您的解释“但这样做我会按县id获取订单，正确的方法是什么以及ASC中的值列表？”。我觉得很不清楚。非常感谢。

SELECT Counties.County_ID, County_Value, COUNT(Customers.County_ID) AS CustCountyCount
FROM Counties 
INNER JOIN Customers
ON Counties.County_ID = Customers.County_ID 
GROUP BY Counties.County_ID, County_Value
ORDER BY County_Value ASC