php - 使用 Laravel 5.2 简化对附加数据的查询

Question

我有一个查询，需要根据第一次查询的结果提供更多信息。这是代码

$params = DB::select('SELECT vpl_ppid, vpl_name, vpl_display, vpl_filter 
                      FROM vw_parameter_list 
                      WHERE vpl_slug = :type', ['type' => $type]);
foreach ($params as $param) {
    $pd_vals = DB::select('SELECT * FROM parameter_distinct_value WHERE pd_ppid = :vpl_ppid ORDER BY pd_value', ['vpl_ppid' => $param->vpl_ppid]);          
    $param->value_list = $pd_vals;
}

正如您在上面看到的，我只需创建一个新数组 ( $param->value_list) 以将更多数据加载到其中。如何通过消除内部查询来简化查询，foreach以实现与上述相同的速度和输出。谢谢

Answer 1

您可以使用子查询：

$results = DB::select('
    SELECT * 
    FROM 
        parameter_distinct_value 
    WHERE pd_ppid IN(
        SELECT vpl_ppid FROM vw_parameter_list WHERE vpl_slug = :type
    ) 
    ORDER BY pd_value
', ['type' => $type]);

或加入

$results = DB::select('
    SELECT pdv.*
    FROM
        parameter_distinct_value pdv
        INNER JOIN vw_parameter_list vpl ON vpl.vpl_ppid = pdv.pd_ppid
    WHERE vpl.vpl_slug = :type
    ORDER BY pdv.pd_value
', ['type' => $type]);