SQL/PHP:在另一个 table 上没有匹配的情况下加入(多个 tables)

SQL/PHP: Joins with no matches on the other table (multiple tables)

我有四个table:

Personal_trainer(personaltrainerID, name, age, location)
Client(clientID, name, age, location)
Nutrition_Plan(NutritionplanID, personaltrainerID, clientID)
Training_Plan(TrainingplanID, personaltrainerID, clientID)

我试图表明,当私人教练创建 nutrition/training 计划并将其分配给客户时,结果只会显示他们的特定客户,但他们在客户中没有外键 table 确定教练(由于项目的标准)

我想知道 training/nutrition 计划中必要加入的 SQL 是什么。我已经尝试了很长一段时间,这是我的示例代码。

期望的输出是所有客户数据,前提是该特定培训师已为他们分配了培训或营养计划

在声明中,我遇到了绑定参数问题,因此只有拥有客户端的用户才能看到他们的客户端。如果我使用指定的 ID,我可以获得 return!

    <?php 
            //code to search for a item from the database
            // user can enter any character to search for a value from the db
           if (isset($_POST['search']))
           {
               $valueToSearch = $_POST['ValueToSearch'];
               $query = "select * from client WHERE concat(`clientID`, `name`, `age`, `sex`, `weight`, `height`, `yearsExperience`, `goal`, `injuries`, 'email')like'%".$valueToSearch."%'";
               $search_result = filterTable($query);

           }
           else {
           $query = "select *
            from client
            where clientID in (select clientID from nutrition_plan where personaltrainerID=?)
            or clientID in (select clientID from training_plan where personalTrainerID=?)";
           $query->bind_param("i", $_POST[""]);
               $search_result = filterTable($query);
           }
           //code to filter the db
           function filterTable($query)
           {
               $connect = mysqli_connect("localhost:3308","root","","fypdatabase");
               $filter_Result = mysqli_query($connect, $query);
               return $filter_Result;
           }
           ?>

           <?php
           while($row = mysqli_fetch_array($search_result))
          { //display the details from the db in the table with option to delete or update entry 
            ?>
                    <tr>
                    <td><?php echo $row["clientID"]; ?></td>
                    <td><?php echo $row["name"]; ?></td>
                    <td><?php echo $row["age"]; ?></td>
                    <td><?php echo $row["sex"]; ?></td>
                    <td><?php echo $row["weight"]; ?></td>
                    <td><?php echo $row["height"]; ?></td>
                    <td><?php echo $row["yearsExperience"]; ?></td>
                    <td><?php echo $row["goal"]; ?></td>
                    <td><?php echo $row["injuries"]; ?></td>
                    <td><?php echo $row["email"]; ?></td>
                    <td> 
                        <a href="?Delete=<?php echo $row["clientID"]; ?>" onclick="return confirm('Are you sure?');">Delete</a>
                    </td>
                    <td>
                        <a href="updateClient.php?Edit=<?php echo $row["clientID"]; ?>" onclick="return confirm('Are you sure?');">Update</a>
                    </td>
                  </tr>
                  <?php

这应该有效

SELECT * from client JOIN nutrition_plan ON client.clientid=nutritionplan.clientid JOIN Personaltrainer ON Personaltrainer.personaltrainerID=nutritionplan.personaltrainerID Where Personaltrainer.personaltrainerID="id"

让我们看看我是否正确理解了您的要求...

仅显示有教练 123 制定的营养或训练计划的客户:

select *
from client
where clientid in (select clientid from nutrition_plan where personaltrainerid = 123)
   or clientid in (select clientid from training_plan where personaltrainerid = 123);

显示这些客户及其所有计划(无论计划的培训师如何):

select *
from client
join
(
  select 'nutrition' as kind, nutritionplanid as id, personaltrainerid, clientid
  from nutrition_plan
  union all
  select 'training' as kind, trainingplanid as id, personaltrainerid, clientid
  from training_plan
) plan using (clientid)
where clientid in (select clientid from nutrition_plan where personaltrainerid = 123)
   or clientid in (select clientid from training_plan where personaltrainerid = 123);
SELECT name, age, location FROM Client
INNER JOIN
(
  SELECT personaltrainerID, clientID from Nutrion_Plan 
  UNION DISTINCT 
  SELECT personaltrainerID, clientID from Training_Plan
) u
USING(clientID)
WHERE u.personaltrainerID = ?;