Data import and export functions of PHP functions

PHP is a programming language widely used in dynamic website development. In PHP, a function is a reusable code block that can improve development efficiency and code quality. Among them, the data import and export functions are particularly commonly used, which can help us quickly export/import data tables into files or databases. Next, let’s take a closer look at the data import and export functions of PHP functions.

1. Data export function

1. fputcsv()

fputcsv() function is one of the most commonly used data export functions in PHP. It converts data in array format to CSV format, which can be saved in a file. Its syntax is as follows:

fputcsv(resource $handle, array $fields, string $delimiter = ',', string $enclosure = '"', string $escape_char = '\')

Among them, $handle is the file pointer, used to specify the file to be written; $fields is the data to be written to the file, passed in array format; $delimiter is the column delimiter of the CSV file, the default is comma; $enclosure is The field delimiter of the CSV file, the default is double quotes; $escape_char is the escape character for escaping special characters in the CSV file, the default is backslash. For example:

// Write data to the CSV file
$fp = fopen('data.csv', 'w');
$data = array(

array('id', 'name', 'age'),
array('1', 'Tom', '20'),
array('2', 'Jerry', '18'),

);
foreach ($data as $fields) {

fputcsv($fp, $fields);

}
fclose($fp);

The above code writes the data in a two-dimensional array $data to the data.csv file.

2. fwrite()

The fwrite() function can also be used for data export. It can write data in a specified format into a text file. Its syntax is as follows:

fwrite( resource $handle, string $string, int $length = null)

Among them, $handle is the file pointer, used to specify the file to be written; $string is the data to be written to the file, in string Format transfer; $length is the number of characters to be written. The default is null, which means writing the entire string. For example:

// Write data to a text file
$fp = fopen('data .txt', 'w');
$data = "ID Name Age
1 Tom 20
2 Jerry 18
";
fwrite($fp, $data);
fclose($fp);

The above code writes a string $data containing header and data into the data.txt file.

2. Data import function

1. fgetcsv()

The fgetcsv() function is one of the most commonly used data reading functions in PHP. It can read data from a CSV file and convert it to Array format. Its syntax is as follows:

fgetcsv(resource $handle, int $length = 0, string $delimiter = ',', string $enclosure = '"', string $escape = '\')

Among them, $handle is the file pointer, used to specify the file to be read; $length is the maximum length of the specified read, the default is 0, which means reading to the end of the file; $delimiter is the column delimiter of the CSV file , the default is comma; $enclosure is the field delimiter of the CSV file, the default is double quotes; $escape is the escape character for escaping special characters in the CSV file, the default is backslash. For example:

/ / Read data from CSV file
$fp = fopen('data.csv', 'r');
while (($data = fgetcsv($fp)) !== false) {

print_r($data);

}
fclose($fp);

The above code will open the data.csv file, read the data line by line and output it, and the data will be returned in array format.

2. file()

The file() function can read the entire file at once and convert it to array format. Its syntax is as follows:

file (string $filename, int $flags = 0, resource $context = null)

Among them, $filename is the file name to be read; $flags is an optional parameter used to specify the returned array type. The default is FILE_USE_INCLUDE_PATH; $context is an optional parameter used to specify the context. For example:

// Read data from the file
$data = file('data.txt');
print_r($data);

The above code will read the entire data.txt file and convert the data into an array format for output.

In summary, the data import of the PHP function The export function can easily export/import data tables into files or databases, greatly improving development efficiency and data processing capabilities. However, it should be noted that when using these functions, you need to pay attention to the correctness of the data format and file path. Permissions.

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