How to convert database into json format file format in php

When developing web applications, it is often necessary to convert data in the database into JSON format so that the front-end page can obtain the data in the database for display and operation. The PHP language provides corresponding function libraries that can help us convert data in the database into JSON format file format.

This article will introduce how to use PHP to convert the database into JSON format file format, including the following aspects:

1. Database connection and data query;
2. Convert the queried data into a PHP array;
3. Use PHP's json_encode() function to convert the PHP array into a JSON string;
4. Save the JSON string into a file format;

1. Database connection and data query

Before conducting database query, you need to connect to the database first. In PHP, you can use mysqli or PDO extension to connect to the database. Here we take the mysqli extension as an example for demonstration.

The sample code is as follows:

<?php
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败：" . $conn->connect_error);
}

// 查询数据库
$sql = "SELECT * FROM your_table";
$result = $conn->query($sql);

// 关闭连接
$conn->close();
?>

2. Convert the queried data into a PHP array

After querying the data in the database, you need to convert it into a PHP array , so that you can use PHP's json_encode() function to convert it into a JSON format string.

The sample code is as follows:

<?php
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败：" . $conn->connect_error);
}

// 查询数据库
$sql = "SELECT * FROM your_table";
$result = $conn->query($sql);

// 将查询到的数据转化为 PHP 数组
$data = array();
if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        $data[] = $row;
    }
}

// 关闭连接
$conn->close();
?>

3. Use PHP's json_encode() function to convert the PHP array into a JSON string

PHP provides the json_encode() function, which can Convert PHP array to JSON string.

The sample code is as follows:

<?php
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败：" . $conn->connect_error);
}

// 查询数据库
$sql = "SELECT * FROM your_table";
$result = $conn->query($sql);

// 将查询到的数据转化为 PHP 数组
$data = array();
if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        $data[] = $row;
    }
}

// 将 PHP 数组转化为 JSON 字符串
$json = json_encode($data);

// 关闭连接
$conn->close();
?>

4. Save the JSON string as a file format

The last step is to save the JSON string as a file format. You can use PHP's file_put_contents () function to implement.

The sample code is as follows:

<?php
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败：" . $conn->connect_error);
}

// 查询数据库
$sql = "SELECT * FROM your_table";
$result = $conn->query($sql);

// 将查询到的数据转化为 PHP 数组
$data = array();
if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        $data[] = $row;
    }
}

// 将 PHP 数组转化为 JSON 字符串
$json = json_encode($data);

// 将 JSON 字符串保存为文件格式
$file = 'your_file_path.json';
file_put_contents($file, $json);

// 关闭连接
$conn->close();
?>

At this point, we have completed the entire process of converting the database into JSON format file format. Through the above code examples, you can clearly understand how to connect the database, query data, convert data into PHP arrays, convert PHP arrays into JSON strings, and save JSON strings in file format in PHP to develop Web The application provides good support.

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