Question

我想创建一个函数来从具有不同表的不同表中获取数据。有可能吗？

这是我的功能代码

<?php
// Check connection

function fetch_data($selectsql){
include 'connectdb.php';
$result = $conn->query($selectsql);
if($result->num_rows <= 0 ){
echo "0 results";
}
else{
while ($row = $result->fetch_assoc()){  
return $row = array();
}
}
}
?>

这是用于测试我的功能

<?php
include 'fetch_data_test.php';
include 'connectdb.php';

$selectsql = "SELECT * FROM user";
$row = fetch_data($selectsql);
echo $name = $row["name"];
echo $lastname = $row["lastname"];
$conn->close();


?>

但它不起作用。有人能帮我吗？或者向我解释一下如何获得和阵列。

错误：

Notice: Undefined index: name in /var/www/html/home/use_fetch.php on line 7 
Notice: Undefined index: lastname in /var/www/html/home/use_fetch.php on line 8

Answer 1

使用此代码return $row = array();时，您将返回一个空白数组。您需要解决此问题。

此外，您没有将返回值保存到任何变量。

在测试功能的代码中，将fetch_data($selectsql);更改为$rows = fetch_data($selectsql);

        <?php
        // Check connection

        function fetch_data($selectsql){

        include 'connectdb.php';
        $rows = array();        
        $result = $conn->query($selectsql);
        if($result->num_rows <= 0 ){
            echo "0 results";

        } else{
            while ($row = $result->fetch_assoc()){  
                  $rows[] = $row;
            }
        }

        $conn->close();
        return $rows;

        }

        ?>

        <?php
        include 'fetch_data_test.php';

        $selectsql = "SELECT * FROM user";
        $rows = fetch_data($selectsql);
        foreach($rows as $row){
            echo $name = $row["name"];
            echo $lastname = $row["lastname"];
            echo "\n";
        }


        ?>

Answer 2

首先，您为函数fetch_data返回空数组。。在while循环之外返回数据

<?php
// Check connection

function fetch_data($selectsql){
 $rows=array();// create an array
include 'connectdb.php';
$result = $conn->query($selectsql);
if($result->num_rows <= 0 ){
echo "0 results";
}
else{
while ($row = $result->fetch_assoc()){  
      $rows= $row;// assign your data to array
}
}
return $rows;// return array
}
?>

其次，您必须将表单函数的返回值分配给变量

<?php
include 'fetch_data_test.php';
include 'connectdb.php'

$selectsql = "SELECT * FROM user";
$row=fetch_data($selectsql);// assing into a variable
echo $name = $row["name"];
echo $lastname = $row["lastname"];
$conn->close();


?>

从不同的表PHP返回数组

2 个答案: