Question

您好，我正在尝试构建IOS应用，我需要获取MySQL数据库的数据。我不知道php。我找到了一个教程https://codewithchris.com/iphone-app-connect-to-mysql-database/ 在创建PHP服务的第3部分中，我将其复制并编辑以获得我的信息。 PHP代码就是这样

<?php

//create connection
$con=mysqli_connect("localhost","myuserid","mypassword","i4142489_wp1");

// Check connection
if (mysqli_connect_errno())
{
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

// This SQL statement selects ALL from the table 'Locations'
$sql = "SELECT * FROM treelibrary";

// Check if there are results
if ($result = mysqli_query($con, $sql))
{
    // If so, then create a results array and a temporary one
    // to hold the data
    $resultArray = array();
    $tempArray = array();

// Loop through each row in the result set
while($row = $result->fetch_object())
{
    // Add each row into our results array
    $tempArray = $row;
    array_push($resultArray, $tempArray);
}

// Finally, encode the array to JSON and output the results
echo json_encode($resultArray);
}

// Close connections
mysqli_close($con);

?>

我将其加载到服务器中，什么也没有，仅弹出空白页...是任何原因还是我的错误在哪里？感谢您的帮助。祝你有美好的一天。

Answer 1

我没有读完整的代码，但是我很确定您正在尝试将结果转换为JSON格式并回显它们。

这是一种简单的方法；

<?php

//
// EDIT: dont use this code, scroll a little bit lower to see the edit I made.
//

//create connection
$con=mysqli_connect("localhost","myuserid","mypassword","i4142489_wp1");

// Check connection
if (mysqli_connect_errno())
{
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

// This SQL statement selects ALL from the table 'Locations'
$sql = "SELECT * FROM treelibrary";

// Executes the SQL statement and puts results into $res
$res = $con->query($sql);

// Checks if there's any rows
if($res->num_rows > 0) {

    // Puts all results in $row
    $row = $res->fetch_assoc();

    // echo & encode datas
    echo json_encode($row);
} else {
    echo "no data found";
}

// Close connections
mysqli_close($con);

编辑：上面的代码确实有效，但仅回显第一行。这是实际上以JSON格式回显所有行的行（已测试）。

<?php

//create connection
$con=mysqli_connect("localhost","myuserid","mypassword","i4142489_wp1");

// Check connection
if (mysqli_connect_errno())
{
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

// This SQL statement selects ALL from the table 'Locations'
$sql = "SELECT * FROM treelibrary";

// Executes the SQL statement and puts results into $res
$res = $con->query($sql);

// Checks if there's any rows
if($res->num_rows > 0) {

    // defines $data
    $data = array();

    // grabs all data and adds them to the $data array
    while ($row =  $res->fetch_assoc()) {
        array_push($data, $row);
    }

    // echo & encode datas
    echo json_encode($data);
} else {
    echo "no data found";
}

// Close connections
mysqli_close($con);

如何使用PHP从MySQL获取数据

1 个答案: