MYSQLI从列中选择字段并从同一个表

Question

在我的查询中，我试图让value attribute_id =＆＃39; 142＆＃39;仅当attribute_id 141 =＆＃39; K＆amp; N＆＃39;

时

如果attribute_id 141 =其他任何内容，例如Flowmaster，那么我不想要attribute_id 142行

不确定我将如何编写此查询。

到目前为止，我正在尝试下面的联接，但它不起作用。

$query = "
SELECT
part.value as part,
brand.value as brand

FROM catalog_product_entity_varchar part

LEFT JOIN catalog_product_entity_varchar brand
ON part.value = 'K&N' AND part.attribute_id = '141'

WHERE part.attribute_id = '142'

LIMIT 0, 2";

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

if (!$result) {
    die('invalid query');
}

while($row = $result->fetch_array(MYSQL_ASSOC)) {
    $part = $row['part'];
}

更新

我想我现在明白了。我把它改成了

$query = "
SELECT
part.value as part,
brand.value as brand

FROM catalog_product_entity_varchar part

JOIN catalog_product_entity_varchar brand
ON part.entity_id = brand.entity_id AND brand.attribute_id = '141' AND brand.value = 'K&N'

WHERE part.attribute_id = '142'

LIMIT 0, 2";

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

if (!$result) {
    die('invalid query');
}

while($row = $result->fetch_array(MYSQL_ASSOC)) {
    $part = $row['part'];
}