Question

大家好，我如何在php的单个查询中组合这3个表？

PHP

<?php  
         $db_name = "atfest_db";  
         $mysql_user = "root";  
         $mysql_pass = "";  
         $server_name = "localhost";  
         $sql =  "SELECT teamone,teamtwo,s_name FROM sport as A right join matches 
       as B right join schedule as C ON A.s_id = B.s_id ORDER by m_id asc";
         $con = mysqli_connect($server_name,$mysql_user,$mysql_pass,$db_name); 
         $result = mysqli_query($con,$sql);


         $response = array();


        while($row=mysqli_fetch_array($result))

        {
        array_push($response, array("teamone"=>$row[0], "teamtwo"=>$row[1], 
        "s_name"=>$row[2]));

        }

        echo json_encode (array("schedule_response"=>$response));




        mysqli_close($con);
        ?>

运动表连接到匹配b s_id，而匹配表通过m_id

连接到计划表

匹配表

日程表

运动表

Answer 1

您可以使用mysql中的join（）连接两个或多个表，如：

select t1.col1, t2.col2 
FROM table1 as t1 JOIN table2 as t2
on t1.some_col = t2.some_col    // where t1, t2 have a common column on which joining is done
where condition;

Reference

Answer 2

请尝试使用此SQL语句：

SELECT B.teamone,B.teamtwo,A.s_name  
FROM sport A  
LEFT JOIN matches B  
LEFT JOIN schedule C  
ON A.s_id = B.s_id  
ORDER by C.m_id asc

Answer 3

SELECT `schedule`.`id`, (and other relevant fields from schedule table), `matches`.`m_id`, `matches`.`teamone`, `matches`.`teamtwo`, (and other relevant fields from matches table), `sport`.`s_id`, (and other relevant fields from sport table)
FROM `sport`
RIGHT JOIN `matches` ON `matches`.`s_id` = `sport`.`s_id`
RIGHT JOIN `schedule` ON `schedule`.`m_id` = `matches`.`m_id`
ORDER BY `schedule`.`id`

上述查询将解决组合三个表的基本问题。但这是一种不好的做法。会有很多冗余数据。您只选择了三列。在那，也没有索引。你无法弄清楚每一行是如何彼此不同的。请提及查询的目的或逻辑。这样我们就可以相应地微调查询。

更新

我已经更新了我们在查询中选择的列。现在，有一个唯一的列计划ID可以唯一标识每一行。您可以根据需要选择其他列。

Answer 4

SELECT teamone，teamtwo，s_name FROM sport A. LEFT JOIN匹配B ON A.m_id = B.m_id LEFT JOIN计划C ON A.s_id = B.s_id ORDER by A.m_id asc

Answer 5

嗨，这是对你的正确查询。您收到错误是因为您没有使用正确的查询..

SELECT teamone，teamtwo，s_name FROM sport as right join匹配为B ON A.s_id = B.s_id右连接时间表为C ON B.m_id = C.m_id order by B.m_id asc

现在您可以通过它来获得适当的结果。此查询是根据您的架构生成的。

如何在php中的一个查询中组合3个表

5 个答案:

更新