在MYSQL中链接两个表：

Question

我有两个表第一个 researchprojects ，其中包含 Publications ，这些是逗号分隔的numberes，在另一个表 publi 我有< em> Pub_id 其中相同的值不是逗号分隔，而其他列如 Pub_year 我的问题是如何链接这两个表并输出 Pub_id ，< em> Pub_year 值？

researchprojects 表

Publications
800, 900, 1000
1000, 1200, 1300

publi 表

Pub_id  Pub_year
800     2015
900     2016
1000    2017
1200    2016
1300    2012

Answer 1

以下是您可以做到的：

在MYSQL中链接两个表：

在MySQL中链接两个表非常容易。每个表中至少有一个列（字段）彼此相似，以便将它们相互关联。

例如：

在你的情况下，你需要像这样使用两个表结构：

Table : researchprojects => id,publications

Table : publi => publi_id,publi_year

您的案例：

在您的情况下，您在一行中提到的所有id's为：

    researchprojects 
         |
         V
---------------------------
publications
800,900,1000
---------------------------

       publi 
         |
         V
---------------------------
publi_id     publi_year
800          2012
800          2013
900          2014
900          2015
1000         2016
1000         2017
---------------------------

显示表数据输出的代码：

<?php
// Assuming that $publications will hold all fetched values from researchprojects table
// Also assuming that $publi will hold all fetched data from publi table
$publi_ids = explode(",",$publications[0]['publications']);
//Now you have all ids in array in $publi_ids
//So moving forward with the code

foreach ($publi_ids  as $publi_id) {
echo "<h1>".$publi_id."</h1>";
$id = $publi_id;
$query = mysqli_query($mysqli,"SELECT * FROM publi WHERE publi_id='$id'");

$publi_data = array();
while ($rows = mysqli_fetch_array($query)) {
  $publi_data[] = $rows;
}

foreach ($publi_data as $publi_row) {
echo "Year :".$publi_row['publi_year']."</br>";
echo "</br></br></br>";
}
echo "</br></br></br></br>";  
} 
?>

输出：

800
Year : 2012
Year : 2013

900
Year : 2014
Year : 2015

1000
Year : 2016
Year : 2017

Answer 2

我已经解决了这个问题！

$query = "SELECT * FROM researchprojects";
$result = mysqli_query($con, $query);
while ($val = mysqli_fetch_array($result))
{
  $Id = $val['Id'];
  $Publications = $val['Publications'];
  $Publication_seprated = explode(',', $Publications);

  foreach($Publication_seprated as $Publication_seprated)
  {
  $query2 = "SELECT * FROM publi WHERE Pub_id = '$Publication_seprated'";
  $result2 = mysqli_query($con, $query2);
  while ($val2 = mysqli_fetch_array($result2))
        {
           $pub_id = $val2['pub_id'];
           $pub_year = $val2['pub_year'];

           echo $pub_year;
          } // while loop


    } // foreach

   } // while loop

Answer 3

创建一个数组，它将以键和值对的形式将pub_id和pub_year存储在数组中

<?php 

$pub = [800 => 2015, 900 => 2016, 1000 => 2017];
foreach ($pub as $pubId => $pubYear) 
{
    echo "<td>{$pubId}, {$pubYear}</td>";
}

?>

SQL，PHP：使用另一个表以逗号分隔值的输出表值

3 个答案:

在MYSQL中链接两个表：