Question

我在数据库中有两个表（table_1和table_2），每个表都有一个名为Name的共有列。

我目前正在使用以下代码仅从Name导入一些数据（status，table_1）：

/* database section start */
    $mysqli = new mysqli("z","z","z","z");

    if (mysqli_connect_errno()) {
        printf("Connect failed: %s\n", mysqli_connect_error());
        exit();
    }
/* database section end */

// Choose Relevant items, and turn them into an array
$item_array = array(
'item1', 
'item2',
'item3'
);

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

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

$result = $mysqli->query("SELECT Name, Status as status from table_1 where Name IN ('$item_implode') ORDER BY FIELD (Name, '$item_implode');");

while($row = $result->fetch_assoc()) {

    $product_name = $row['Name'];
    // find all keys in $item_array which value is the products
        $keys = array_keys($item_array, $product_name);
    foreach ($keys as $key) {

        // add values for these keys
        $product[$key + 1]["Name"] = $row['Name'];
        $product[$key + 1]["status"] = $row['status'];//

    }
}

我也希望从table_2导入数据（例如，名为color，date_added的列

我的目标是拥有这些钥匙：

$product[$x]["Name"]
$product[$x]["status"]
$product[$x]["color"]
$product[$x]["date_added"]

我已尝试以这种形式使用UNION，但在最后一行上遇到致命错误：

$result = $mysqli->query

("(SELECT Name, status as status from table_1 where Name IN ('$item_implode') ORDER BY FIELD (Name, '$item_implode') ) 
UNION (SELECT color from table_2  where Name IN ('$item_implode') ORDER BY FIELD (Name, '$item_implode') );");

while($row = $result->fetch_assoc()) {

编辑：

TABLE_1：

+-------+-------------+------+-----+---------+----------------+
| Name  | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+           
| Name  | varchar(100)| NO   |     | None    |                |
| status| varchar(5)  | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+

TABLE_2：

+-------+-------------+------+-----+---------+----------------+
| Name  | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+           
| Name  | varchar(100)| YES  |     | NULL    |                |
| color | varchar(5)  | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+

更新

尝试使用此：

$result = $mysqli->query

("SELECT Name, status as status, color as color table_1 
JOIN table_2 ON table_1.Name=table_2.Name 
WHERE table_1.Name IN ('$item_implode') 
ORDER BY FIELD (table_1.Name, '$item_implode') ;" );

while($row = $result->fetch_assoc()) {

得到了

致命错误：在非对象
上调用成员函数fetch_assoc（）

Answer 1

首先是那些mysqli连接参数是什么？它们应该是 - ＆gt; $conn = new mysqli($servername, $username, $password, $dbname);

第二个UNION结合了两个或多个SELECT语句的结果，你最需要的是一个Join Query！这就像

SELECT Orders.OrderID, Customers.CustomerName, Orders.OrderDate FROM Orders INNER JOIN Customers ON Orders.CustomerID=Customers.CustomerID;

Answer 2

您是不是在第一次查询中遗漏了FROM单词？

("(SELECT Name, status as status table_1 where Name IN ('$item_implode') ORDER BY FIELD (Name, '$item_implode') ) UNION (SELECT color from table_2  where Name IN ('$item_implode') ORDER BY FIELD (Name, '$item_implode') );");

Answer 3

$result = $mysqli->query("
    SELECT Name, status as status, color 
    FROM table_1 
    JOIN table_2 ON table_1.Name=table_2.Name 
    WHERE table_1.Name IN ('$item_implode') 
    ORDER BY FIELD (table_1.Name, '$item_implode')
");

此查询应该适合您。我说应该因为我不能在没有看到表结构，数据和预期结果的情况下测试它。此查询将为第一个表中的每个项返回一行，该行在第二个表中具有相应的行。该对应关系基于两个表中具有相同的名称

UNION与Where - 致命错误

3 个答案: