Question

我有两个桌子。

1-汽车（列：ID，名称，描述，图像）

2-摩托车（列：ID，名称，描述，图像）

我想在Vehicles.php页面上循环两个表。我想按循环中的ID排序。

我的代码

CARS

$cars= $baglan->query("SELECT * FROM Cars ORDER BY id", PDO::FETCH_ASSOC);      
if ( $cars->rowCount() )
foreach( $cars as $car){ 
-
}}

摩托车

$query= $baglan->query("SELECT * FROM Motorcycles ORDER BY id", PDO::FETCH_ASSOC);      
if ( $query->rowCount() )
foreach( $query as $row){ 
-
}}

如何合并这两个查询？

此代码无效

   $vehicles= $baglan->query("SELECT * FROM Motorcycles , Cars ORDER BY id", PDO::FETCH_ASSOC);     
    if ( $vehicles->rowCount() )
    foreach( $vehicles as $vehicle){ 
    -
    }}

谢谢

Answer 1

由于它们具有相同的列，因此您可以使用MATCH (n:Owner) WHERE (n)-[:OWNS]->(:Vehicles) RETURN DISTINCT n.email, n.name ORDER BY n.name

UNION

Answer 2

如果要在一个查询中合并它们，则可以在mysql中使用UNION，但我强烈建议您仅在两个表的列相同的情况下使用它。

try {
    $vehicles = $baglan->query("
        SET @id:=0;
        SELECT (@id:=@id+1) AS `ID`,`Name`,`Description`,`Image` FROM (
            (SELECT * FROM `Cars` ORDER BY `ID`)
            UNION
            (SELECT * FROM `Motorcycles` ORDER BY `ID`)
        ) AS `Vehicles`;
    ", PDO::FETCH_ASSOC);
    if ($vehicles->rowCount()) {
        $id = 1;
        foreach($vehicles as $vehicle) { 
            echo $id++; // Use $id because the `id` column is from two tables
            // use other fields normally
        }
    }
} catch (Exception $e) {
    echo $e->getMessage();
}

但是，如果您想在原始ID列上排序混合数据，则可以使用它（例如，降序）：

try {
    $vehicles = $baglan->query("
        SELECT * FROM (
            (SELECT * FROM `Cars` ORDER BY `ID` DESC)
            UNION
            (SELECT * FROM `Motorcycles` ORDER BY `ID` DESC)
        ) AS `Vehicles`
        ORDER BY `ID` DESC;
    ", PDO::FETCH_ASSOC);
    if ($vehicles->rowCount()) {
        $id = 1;
        foreach($vehicles as $vehicle) { 
            echo $id++; // Use $id because the `id` column is from two tables
            // use other fields normally
        }
    }
} catch (Exception $e) {
    echo $e->getMessage();
}

Answer 3

您可以使用以下查询：

SELECT * FROM(
SELECT * FROM Motorcycles
UNION
SELECT * FROM Cars)
ORDER BY ID

订购联合查询

3 个答案: