相关疑难解决方法(0)

我正在运行以下MySQL查询来查找没有手册(并且有黑色轮子等)的汽车

SELECT `cars`.* FROM `cars`
INNER JOIN wheels ON cars.id = wheels.car_id
LEFT OUTER JOIN manuals ON cars.id = manuals.car_id
WHERE (cars.created_at > '2010-09-09'
AND wheels.color = 'Black'
AND wheels.created_at < '2011-01-05'
AND manuals.car_id IS NULL)

查询的结果看起来是正确的,但它返回id为27的汽车两次.如何更改查询以使所有结果都是唯一的(无重复)？

我有一个包含多个条目的数据库.我感兴趣的一个特定的条目列被称为sample_group.如果有10行条目sample_group,我试图使用PHP创建一个唯一条目的数组.

例如,条目将是"food", "food", "water", "food", "swabs", "swabs", "swabs", "food", "water", "water"和创建数组后应该是:array("food", "water", "swabs").

这是我尝试过的代码,它有点工作,但数组末尾有一个空条目:

 $sql3 = "SELECT * FROM samples_database WHERE order_id=$order_id;";
  $result3 = mysqli_query($conn, $sql3); 
$group_array = '';
  while ($input = mysqli_fetch_array($result3)) {
    $group_array .= $input['sample_group'] . ',';
  }
  $group_array2 = array_filter(array_unique(explode(',', $group_array)));

然后是foreach循环:

foreach ($group_array2 as $group) {
//do something
}

任何人都可以把我推向正确的方向吗？

可能重复:
MySQL:仅从列中选择唯一值

我从mysql表类别和列父级获取值.父包含值1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4

如果他们重复,我想跳过这些值.所以我希望输出为1,2,3,4

请帮帮我..我的代码不是在woking.

$new_cat1 = $cat1;
    foreach($cat1 as $category){
        $query="SELECT parent FROM categories where id='$category'";
        $result = mysql_query($query);  
        $line = mysql_fetch_assoc($result);
        array_push($new_cat1,$line['parent']);
        if (in_array("1", $new_cat1)) {
        continue;
        }
    }

好吧,所以我一直试图弄清楚这两天没有真正的成功

这是我的代码

$splash_list = '';

$splash_array = array();

$sql = "SELECT * FROM pm WHERE receiver='$username' OR sender='$username'";
$query = mysqli_query($db, $sql);
while($row = mysqli_fetch_array($query, MYSQLI_ASSOC)){
        if($username == $row['sender']){
                $otuser = array_push($splash_array, $row['receiver']);
                $this_user = $row['sender'];
        } else {
                $otuser = array_push($splash_array, $row['sender']);
                $this_user = $row['receiver'];
        }

 }
foreach($splash_array as $otuser){
        $splash_list .= '<div>'.$otuser.'<br></div>';
}      

输出是otuser1 otuser1 otuser1 otuser2 otuser2

如果任何人可以给我一个关于我如何只是输出每个值的指针otuser1 otuser2

非常感谢:)