数组中对象的名称导致顺序发生变化

Question

使用以下代码：

//turn items into an array
$item_array = array('abc','xyz2','Good','nice-b');

//implode items, turn into string
$item_implode = join("','", $item_array);

//declare an overall array for result
$product_items = array();

$productList = array();
$result = $mysqli->query("SELECT Name, WebsitePrice as price, WebsiteStock as stock from table_products where Name IN ('$item_implode')");

if ($result->num_rows > 0) {
    $x = 1;
    // output data of each row
    while($row = $result->fetch_assoc()) {
        $product_items[$x]["Name"] = $row['Name'];
        $product_items[$x]["price"] = $row['price'];
        $product_items[$x]["stock"] = $row['stock'];
        $x = $x + 1;
    }
} else {
    echo "0 results";
}

我得到这个输出：

abc- 99 - yes
xyz - 20 - yes
Good - 30 - yes
nice-b - 55 - yes

但是当我使用名为 Hello1 而不是 Good 的项目时，像这样：

$item_array = array('abc','xyz2','Hello1','nice-b');

我得到这个输出：

abc- 99 - yes
Hello1 - 77 - yes
xyz - 20 - yes
nice-b - 55 - yes

意思是对象的名字引起了数组顺序的一些变化，变成了second项，尽管它应该是 第三个。

这是什么原因造成的？

Answer 1

In the SQL world, order is not an inherent property of a set of data. Thus, you get no guarantees from your RDBMS that your data will come back in a certain order -- or even in a consistent order -- unless you query your data with an ORDER BY clause.

无法保证 MySQL 将 return 结果按照您在 IN 子句中设置 ID 的顺序。

稍后编辑：根据您最后的评论，您可以这样做：

if ($result->num_rows > 0) {
    $product_items = array_flip($item_array);

    // output data of each row
    while($row = $result->fetch_assoc()) {
        $product_items[$row['Name']] = array();

        $product_items[$row['Name']]["Name"]  = $row['Name'];
        $product_items[$row['Name']]["price"] = $row['price'];
        $product_items[$row['Name']]["stock"] = $row['stock'];
    }
}

Answer 2

在查询中使用 ORDER BY FIELD(Name, 'abc','xyz2','Good','nice-b');。您可以使用 $item_implode 来实现可重用性。

[摘自评论]

数组中对象的名称导致顺序发生变化

Name of object in array causes a change in order

php

arrays

sorting

dynamic-arrays