php - 如何在执行多个查询时返回多个结果？

Question

我正在一个函数内执行 4 个查询。如何一次返回这 4 个结果，以便在调用函数时可以使用所有 4 个结果？我应该创建一个数组并将所有结果存储在该数组中吗？我尝试一一返回结果，但在调用 return 命令后，函数从该点退出。有没有办法单独返回每个查询结果？这是我的代码:

function select_all_category_name() {
        require 'admin/db_connect.php'; 
        $sql="SELECT * FROM tbl_category WHERE publication_status=1 AND deletion_status=1";

        if (mysqli_query($db_connect, $sql)) {

            $sql1="SELECT * FROM tbl_category WHERE publication_status=1 AND deletion_status=1 AND mpid='' AND spid='' AND pid=''";
            $sql2="SELECT * FROM tbl_category WHERE publication_status=1 AND deletion_status=1 AND mpid!='' AND spid='' AND pid=''";
            $sql3="SELECT * FROM tbl_category WHERE publication_status=1 AND deletion_status=1 AND mpid!='' AND spid!='' AND pid=''";
            $sql4="SELECT * FROM tbl_category WHERE publication_status=1 AND deletion_status=1 AND mpid!='' AND spid!='' AND pid!=''";
            $query_result1=mysqli_query($db_connect, $sql1);
            $query_result2=mysqli_query($db_connect, $sql2);
            $query_result3=mysqli_query($db_connect, $sql3);
            $query_result4=mysqli_query($db_connect, $sql4);


        } else {
            die("Query Problem". mysqli_error($db_connect));
        }
    }

db_connect.php 文件包含连接。

Answer 1

使用数组:

function select_all_category_name() {
    require 'admin/db_connect.php'; 
    $sql="SELECT * FROM tbl_category WHERE publication_status=1 AND deletion_status=1";

    if (mysqli_query($db_connect, $sql)) {
        $ret = [
             "{$sql} AND mpid ='' AND spid ='' AND pid =''",
             "{$sql} AND mpid!='' AND spid ='' AND pid =''",
             "{$sql} AND mpid!='' AND spid!='' AND pid =''",
             "{$sql} AND mpid!='' AND spid!='' AND pid!=''",
        ];
        foreach ($ret as $i => $sqlx) {
            $ret[$i] = mysqli_query($db_connect, $sqlx);
        };
        return $ret;
    }
    return false;
}

或者您可以对整个函数使用单个查询(如果没有找到任何内容，它将返回一个空数组):

SELECT
    CASE 
        WHEN mpid='' AND spid='' AND pid='' THEN 0,
        WHEN mpid!='' AND spid='' AND pid='' THEN 1,
        WHEN mpid!='' AND spid!='' AND pid='' THEN 2,
        WHEN mpid!='' AND spid!='' AND pid!='' THEN 3
        ELSE -1
    END AS idx,
    *
FROM tbl_category 
WHERE publication_status=1 AND deletion_status=1
HAVING idx != -1