PHP reads file content: detailed process and method for data import and parsing

PHP reads file content: detailed processes and methods to implement data import and parsing

In web development, it is often necessary to read the content of external files for data import. and analysis. For example, import data from Excel files to the database, or parse data from CSV files for display, etc. This article will introduce the detailed process and method of using PHP to read file content, import and parse data.

1. File reading method

In PHP, there are many ways to read the contents of the file. Commonly used methods include: file_get_contents(), fopen() with fgets(), etc. Below we will introduce two of the commonly used methods.

1. Use file_get_contents()

The file_get_contents() function is used to read the contents of the entire file and return it as a string. It can accept a file name as a parameter and returns the file content string. The following is a simple example:

$file_path = 'data.txt';
$file_content = file_get_contents($file_path);
echo $file_content;

In the above example, we read the file named data.txt, save its content in the $file_content variable, and then output the content to the browser.

2. Use fopen() and fgets()

The fopen() function is used to open a file or URL and returns a file resource or false. The fgets() function is used to read a line from an open file resource. The following is a simple example:

$file_path = 'data.txt';
$file_handle = fopen($file_path, 'r');

while (!feof($file_handle)) {
    $line = fgets($file_handle);
    echo $line;
}

fclose($file_handle);

In the above example, we first use the fopen() function to open the file named data.txt, and save the returned file resource in the $file_handle variable. Then use fgets() to read the file content line by line in the while loop and output it to the browser. Finally, use the fclose() function to close the file resource.

2. Data import and parsing methods

After reading the file content, we can import or parse the data. Here are two commonly used methods.

1. Data import

Data import is usually used to import data from files into the database. In practical applications, corresponding parsing and processing can be performed according to the file format and database structure. Here is an example that will read data from a CSV file and then insert it into the database:

$file_path = 'data.csv';
$file_handle = fopen($file_path, 'r');

// 连接数据库
$mysqli = new mysqli('localhost', 'username', 'password', 'database');

// 检查连接是否成功
if ($mysqli->connect_error) {
    die('连接数据库失败：' . $mysqli->connect_error);
}

// 遍历文件内容
while (($data = fgetcsv($file_handle)) !== false) {
    $name = $data[0];
    $email = $data[1];
    
    // 插入数据
    $sql = "INSERT INTO users (name, email) VALUES ('$name', '$email')";
    $mysqli->query($sql);
}

// 关闭文件资源和数据库连接
fclose($file_handle);
$mysqli->close();

In the above example, we first open the CSV file named data.csv using the fopen() function. Then use the fgetcsv() function to read the file content line by line and insert it into the database. Finally, use the fclose() function to close the file resource and $mysqli->close() to close the database connection.

2. Data analysis

Data analysis is usually used to process the data in the file and display it on the web page. The following is an example that will read data from an Excel file and display it on the web page in tabular form:

$file_path = 'data.xlsx';

// 解析Excel文件内容
$spreadsheet = PhpOfficePhpSpreadsheetIOFactory::load($file_path);
$worksheet = $spreadsheet->getActiveSheet();
$highest_row = $worksheet->getHighestRow();

echo '<table>';

// 遍历文件内容
for ($row = 1; $row <= $highest_row; $row++) {
    echo '<tr>';
    
    $cellA = $worksheet->getCell('A' . $row)->getValue();
    echo '<td>' . $cellA . '</td>';
    
    $cellB = $worksheet->getCell('B' . $row)->getValue();
    echo '<td>' . $cellB . '</td>';
    
    // 其他单元格...
    
    echo '</tr>';
}

echo '</table>';

In the above example, we use the PhpSpreadsheet library to parse the Excel file content and display it on on the web page. Obtain the value of the specified cell by using the getCell() function, and build the table structure using the getTable() function.

Summary:

This article introduces the detailed process and method of using PHP to read file content and implement data import and parsing. We introduced two commonly used file reading methods: file_get_contents(), fopen() and fgets(), as well as sample code for data import and parsing. Through learning and practice, I believe you can flexibly apply these methods in actual development and improve your development efficiency.

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