Question

我还在学习SQL查询。我试过在网上搜索，但我甚至不知道我应该搜索什么条款，所以我正在找人指出我正确的方向。我有两张桌子 - 约会和登录。我正在尝试使用concat函数来获取“apptFor”和“addedBy”的名字和姓氏。我需要单独查询吗？它似乎应该可以在一个查询中完成。

<table border="1">
   <tbody>
     <tr>
       <td width="140" align="center"><strong>Appt Date/Time</strong></td>
       <td width="100" align="center"><strong>Appt For</strong></td>
       <td width="300" align="center"><strong>Appointment</strong></td>
       <td width="100" align="center"><strong>Added By</strong></td>
       <td width="100" align="center"><strong>Date Added</strong></td>
     </tr>
     <?php
            $query = "SELECT a.appID,a.appDate,a.appNote,a.apptFor,a.addedBy,a.added,concat(u.firstName,' ',u.lastName) as appAddedBy FROM appointments a ";
            $query .=" INNER JOIN logins u on a.addedBy=u.userid WHERE a.userID='$uid' order by appDate asc";
            $result = mysqli_query($con, $query);
        if(mysqli_num_rows($result) > 0)
        {
            while($row = mysqli_fetch_assoc($result))
            {
    ?>
     <tr>
       <td><?php echo $row['appDate']; ?></td>
       <td><?php echo $row['apptFor']; ?></td>
       <td><?php echo $row['appNote']; ?></td>
       <td><?php echo $row['appAddedBy']; ?></td>
       <td><?php echo $row['added']; ?></td>
     </tr>
     <?php  }} ?>
   </tbody>
 </table>

Answer 1

如果你需要两个名字，你应该加入两次登录

     $query = "SELECT a.appID,a.appDate,a.appNote,a.apptFor,a.addedBy
            ,a.added,concat(u1.firstName,' ',u1.lastName) as appAddedBy  
              ,concat(u2.firstName,' ',u2.lastName) as appApptFor 
            FROM appointments a ";
        $query .=" INNER JOIN logins u1 on a.addedBy=u1.userid";
        $query .=" INNER JOIN logins u2 on a.apptFor=u2.userid 
                  WHERE a.userID='$uid' ";
        order by appDate asc";
        $result = mysqli_query($con, $query);

SQL join concat有两个不同的值

1 个答案: