如何回显来自2个不同表的值？

Question

我有2个表，我想要回显这2个表中的值。

安排表

计划表

这是我的代码，

<?php
    if (!mysqli_connect_errno($con)) {
        $sqlQueryStr = "SELECT * FROM scheduletime ST, schedule S WHERE ST.schedule_Id = S.schedule_Id AND ST.staff_Id= $id  AND ST.Monday= '1' ";

        $result = mysqli_query($con, $sqlQueryStr);

        while ($row = mysqli_fetch_array($result)) {
            $button[$row['scheduleTime_Id']] = $row;
        }

        mysqli_close($con);
    } else {
        echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }

foreach ($button as $id => $info) {
    echo $id;
    echo $info['startTime']; //startTime is from scheduletime table
    echo $info['endTime']; //endTime is from scheduletime table
    echo $info['academicInstitution']; //academicInstitution is from schedule table
    echo '</br>';
}

我能够回显“scheduletime”中的值，而不是“schedule”。如何回显2个不同表中的值？