如何为 wp_rest_api 连接两个 MySQL 表答案

【问题标题】：How to join two MySQL tables for wp_rest_api如何为 wp_rest_api 连接两个 MySQL 表
【发布时间】：2020-09-10 06:42:34
【问题描述】：

在我的 WordPress 数据库中，我有三个表 wp_companies 存储一些公司信息和 wp_product_types 存储公司可以自己分配的一堆产品类型然后我有 wp_company_products 用于使用 id 将产品类型分配给公司。

这是数据库外观的示例：

wp_companies

id | company_name | member_type | logo
-----------------------------------------------------------------
1  | Google       | full        | https://via.placeholder.com/150
-----------------------------------------------------------------
2  | Crunchyroll  | full        | https://via.placeholder.com/150

wp_products

id | product_name    |
----------------------
1  | Car Insurance   |
----------------------
2  | House Insurance |
----------------------
3  | Life Insurance  |

wp_company_products

id | company_id | product_id 
----------------------------
1  | 1          | 2
----------------------------
2  | 2          | 1
----------------------------
3  | 1          | 3

这是我当前的 MySQL 查询，它只显示 wp_companies 中的数据

    add_action('rest_api_init', function() {
        register_rest_route('custom-routes/v1', 'members', array(
            'methods' => 'GET',
            'callback' => 'get_members'
        ) );
    });

    function get_members($data) {
        global $wpdb;

        $query = $wpdb->get_results( "SELECT company_name, member_type, logo, site_url FROM {$wpdb->prefix}companies ORDER BY RAND()" );

        foreach ( $query as $member ) {
            $member_data[] = array(
                "company_name" => $member->company_name,
                "member_type" => $member->member_type,
                "logo" => $member->logo,
            );
        }

        return $member_data;
    }

这会在我的 api 端点上显示我的数据：

[
    {
        "company_name":"Google",
        "member_type":"full",
        "logo":"https://via.placeholder.com/150",
    },
    {
        "company_name":"Crunchyroll",
        "member_type":"full",
        "logo":"https://via.placeholder.com/150",
    }
]

但我想要的是合并 wp_companies 和 wp_company_products 表，以便我的数据在 api 端点上显示如下：

[
    {
        "company_name":"Google",
        "member_type":"full",
        "logo":"https://via.placeholder.com/150",
        "products": [
            "House Insurance",
            "Life Insurance"
         ]
    },
    {
        "company_name":"Crunchyroll",
        "member_type":"full",
        "logo":"https://via.placeholder.com/150",
        "products": [
            "Car Insurance",
         ]
    }
]

如何构建我的 MySQL 查询以实现此目的？

【问题讨论】：

标签： php mysql wordpress wordpress-rest-api

【解决方案1】：

请试试这个

function get_members($data) {
    global $wpdb;

    $query = $wpdb->get_results( "SELECT company_name, member_type, logo, site_url FROM {$wpdb->prefix}companies ORDER BY RAND()" );

    foreach ( $query as $member ) {
        $productQuery = $wpdb->get_results( "SELECT product_name FROM wp_products WHERE id IN (SELECT product_id from wp_company_products WHERE compony_id = '{$member->id}') " );
        $products = array();
        foreach ( $productQuery as $prduct ) {
            array_push($products ,$prduct->product_name);
        }

        $member_data[] = array(
            "company_name" => $member->company_name,
            "member_type" => $member->member_type,
            "logo" => $member->logo,
            "products" => $products
        );
    }

    return $member_data;
}

【讨论】：