search

friends-of-reactphp / mysql

Async MySQL database client for ReactPHP.
MIT License
334 stars 66 forks source link

readme

MySQL

CI status

Async MySQL database client for ReactPHP.

Development version: This branch contains the code for the upcoming version 0.7 release. For the code of the current stable version 0.6 release, check out the 0.6.x branch.

The upcoming version 0.7 release will be the way forward for this package. However, we will still actively support version 0.6 for those not yet on the latest version. See also installation instructions for more details.

This is a MySQL database driver for ReactPHP. It implements the MySQL protocol and allows you to access your existing MySQL database. It is written in pure PHP and does not require any extensions.

Table of contents

Quickstart example

This example runs a simple SELECT query and dumps all the records from a book table:

<?php

require __DIR__ . '/vendor/autoload.php';

$mysql = new React\Mysql\MysqlClient('user:pass@localhost/bookstore');

$mysql->query('SELECT * FROM book')->then(
    function (React\Mysql\MysqlResult $command) {
        print_r($command->resultFields);
        print_r($command->resultRows);
        echo count($command->resultRows) . ' row(s) in set' . PHP_EOL;
    },
    function (Exception $error) {
        echo 'Error: ' . $error->getMessage() . PHP_EOL;
    }
);

See also the examples.

Usage

MysqlClient

The MysqlClient is responsible for exchanging messages with your MySQL server and keeps track of pending queries.

$mysql = new React\Mysql\MysqlClient($uri);

$mysql->query(…);

This class represents a connection that is responsible for communicating with your MySQL server instance, managing the connection state and sending your database queries. Internally, it creates the underlying database connection only on demand once the first request is invoked on this instance and will queue all outstanding requests until the underlying connection is ready. This underlying connection will be reused for all requests until it is closed. By default, idle connections will be held open for 1ms (0.001s) when not used. The next request will either reuse the existing connection or will automatically create a new underlying connection if this idle time is expired.

From a consumer side this means that you can start sending queries to the database right away while the underlying connection may still be outstanding. Because creating this underlying connection may take some time, it will enqueue all outstanding commands and will ensure that all commands will be executed in correct order once the connection is ready.

If the underlying database connection fails, it will reject all outstanding commands and will return to the initial "idle" state. This means that you can keep sending additional commands at a later time which will again try to open a new underlying connection. Note that this may require special care if you're using transactions that are kept open for longer than the idle period.

Note that creating the underlying connection will be deferred until the first request is invoked. Accordingly, any eventual connection issues will be detected once this instance is first used. You can use the quit() method to ensure that the connection will be soft-closed and no further commands can be enqueued. Similarly, calling quit() on this instance when not currently connected will succeed immediately and will not have to wait for an actual underlying connection.

__construct()

The new MysqlClient(string $uri, ConnectorInterface $connector = null, LoopInterface $loop = null) constructor can be used to create a new MysqlClient instance.

The $uri parameter must contain the database host, optional authentication, port and database to connect to:

$mysql = new React\Mysql\MysqlClient('user:secret@localhost:3306/database');

Note that both the username and password must be URL-encoded (percent-encoded) if they contain special characters:

$user = 'he:llo';
$pass = 'p@ss';

$mysql = new React\Mysql\MysqlClient(
    rawurlencode($user) . ':' . rawurlencode($pass) . '@localhost:3306/db'
);

You can omit the port if you're connecting to default port 3306:

$mysql = new React\Mysql\MysqlClient('user:secret@localhost/database');

If you do not include authentication and/or database, then this method will default to trying to connect as user root with an empty password and no database selected. This may be useful when initially setting up a database, but likely to yield an authentication error in a production system:

$mysql = new React\Mysql\MysqlClient('localhost');

This method respects PHP's default_socket_timeout setting (default 60s) as a timeout for establishing the underlying connection and waiting for successful authentication. You can explicitly pass a custom timeout value in seconds (or use a negative number to not apply a timeout) like this:

$mysql = new React\Mysql\MysqlClient('localhost?timeout=0.5');

By default, idle connections will be held open for 1ms (0.001s) when not used. The next request will either reuse the existing connection or will automatically create a new underlying connection if this idle time is expired. This ensures you always get a "fresh" connection and as such should not be confused with a "keepalive" or "heartbeat" mechanism, as this will not actively try to probe the connection. You can explicitly pass a custom idle timeout value in seconds (or use a negative number to not apply a timeout) like this:

$mysql = new React\Mysql\MysqlClient('localhost?idle=10.0');

By default, the connection provides full UTF-8 support (using the utf8mb4 charset encoding). This should usually not be changed for most applications nowadays, but for legacy reasons you can change this to use a different ASCII-compatible charset encoding like this:

$mysql = new React\Mysql\MysqlClient('localhost?charset=utf8mb4');

If you need custom connector settings (DNS resolution, TLS parameters, timeouts, proxy servers etc.), you can explicitly pass a custom instance of the ConnectorInterface:

$connector = new React\Socket\Connector([
    'dns' => '127.0.0.1',
    'tcp' => [
        'bindto' => '192.168.10.1:0'
    ],
    'tls' => [
        'verify_peer' => false,
        'verify_peer_name' => false
    )
]);

$mysql = new React\Mysql\MysqlClient('user:secret@localhost:3306/database', $connector);

This class takes an optional LoopInterface|null $loop parameter that can be used to pass the event loop instance to use for this object. You can use a null value here in order to use the default loop. This value SHOULD NOT be given unless you're sure you want to explicitly use a given event loop instance.

query()

The query(string $query, array $params = []): PromiseInterface<MysqlResult> method can be used to perform an async query.

This method returns a promise that will resolve with a MysqlResult on success or will reject with an Exception on error. The MySQL protocol is inherently sequential, so that all queries will be performed in order and outstanding queries will be put into a queue to be executed once the previous queries are completed.

$mysql->query('CREATE TABLE test ...');
$mysql->query('INSERT INTO test (id) VALUES (1)');

If this SQL statement returns a result set (such as from a SELECT statement), this method will buffer everything in memory until the result set is completed and will then resolve the resulting promise. This is the preferred method if you know your result set to not exceed a few dozens or hundreds of rows. If the size of your result set is either unknown or known to be too large to fit into memory, you should use the queryStream() method instead.

$mysql->query($query)->then(function (React\Mysql\MysqlResult $command) {
    if (isset($command->resultRows)) {
        // this is a response to a SELECT etc. with some rows (0+)
        print_r($command->resultFields);
        print_r($command->resultRows);
        echo count($command->resultRows) . ' row(s) in set' . PHP_EOL;
    } else {
        // this is an OK message in response to an UPDATE etc.
        if ($command->insertId !== 0) {
            var_dump('last insert ID', $command->insertId);
        }
        echo 'Query OK, ' . $command->affectedRows . ' row(s) affected' . PHP_EOL;
    }
}, function (Exception $error) {
    // the query was not executed successfully
    echo 'Error: ' . $error->getMessage() . PHP_EOL;
});

You can optionally pass an array of $params that will be bound to the query like this:

$mysql->query('SELECT * FROM user WHERE id > ?', [$id]);

The given $sql parameter MUST contain a single statement. Support for multiple statements is disabled for security reasons because it could allow for possible SQL injection attacks and this API is not suited for exposing multiple possible results.

queryStream()

The queryStream(string $sql, array $params = []): ReadableStreamInterface method can be used to perform an async query and stream the rows of the result set.

This method returns a readable stream that will emit each row of the result set as a data event. It will only buffer data to complete a single row in memory and will not store the whole result set. This allows you to process result sets of unlimited size that would not otherwise fit into memory. If you know your result set to not exceed a few dozens or hundreds of rows, you may want to use the query() method instead.

$stream = $mysql->queryStream('SELECT * FROM user');
$stream->on('data', function ($row) {
    echo $row['name'] . PHP_EOL;
});
$stream->on('end', function () {
    echo 'Completed.';
});

You can optionally pass an array of $params that will be bound to the query like this:

$stream = $mysql->queryStream('SELECT * FROM user WHERE id > ?', [$id]);

This method is specifically designed for queries that return a result set (such as from a SELECT or EXPLAIN statement). Queries that do not return a result set (such as a UPDATE or INSERT statement) will not emit any data events.

See also ReadableStreamInterface for more details about how readable streams can be used in ReactPHP. For example, you can also use its pipe() method to forward the result set rows to a WritableStreamInterface like this:

$mysql->queryStream('SELECT * FROM user')->pipe($formatter)->pipe($logger);

Note that as per the underlying stream definition, calling pause() and resume() on this stream is advisory-only, i.e. the stream MAY continue emitting some data until the underlying network buffer is drained. Also notice that the server side limits how long a connection is allowed to be in a state that has outgoing data. Special care should be taken to ensure the stream is resumed in time. This implies that using pipe() with a slow destination stream may cause the connection to abort after a while.

The given $sql parameter MUST contain a single statement. Support for multiple statements is disabled for security reasons because it could allow for possible SQL injection attacks and this API is not suited for exposing multiple possible results.

ping()

The ping(): PromiseInterface<void> method can be used to check that the connection is alive.

This method returns a promise that will resolve (with a void value) on success or will reject with an Exception on error. The MySQL protocol is inherently sequential, so that all commands will be performed in order and outstanding command will be put into a queue to be executed once the previous queries are completed.

$mysql->ping()->then(function () {
    echo 'OK' . PHP_EOL;
}, function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

quit()

The quit(): PromiseInterface<void> method can be used to quit (soft-close) the connection.

This method returns a promise that will resolve (with a void value) on success or will reject with an Exception on error. The MySQL protocol is inherently sequential, so that all commands will be performed in order and outstanding commands will be put into a queue to be executed once the previous commands are completed.

$mysql->query('CREATE TABLE test ...');
$mysql->quit();

This method will gracefully close the connection to the MySQL database server once all outstanding commands are completed. See also close() if you want to force-close the connection without waiting for any commands to complete instead.

close()

The close(): void method can be used to force-close the connection.

Unlike the quit() method, this method will immediately force-close the connection and reject all outstanding commands.

$mysql->close();

Forcefully closing the connection will yield a warning in the server logs and should generally only be used as a last resort. See also quit() as a safe alternative.

error event

The error event will be emitted once a fatal error occurs, such as when the connection is lost or is invalid. The event receives a single Exception argument for the error instance.

$mysql->on('error', function (Exception $e) {
    echo 'Error: ' . $e->getMessage() . PHP_EOL;
});

This event will only be triggered for fatal errors and will be followed by closing the connection. It is not to be confused with "soft" errors caused by invalid SQL queries.

close event

The close event will be emitted once the connection closes (terminates).

$mysql->on('close', function () {
    echo 'Connection closed' . PHP_EOL;
});

See also the close() method.

Install

The recommended way to install this library is through Composer. New to Composer?

Once released, this project will follow SemVer. At the moment, this will install the latest development version:

composer require react/mysql:^0.7@dev

See also the CHANGELOG for details about version upgrades.

This project aims to run on any platform and thus does not require any PHP extensions and supports running on legacy PHP 5.4 through current PHP 8+ and HHVM. It's highly recommended to use the latest supported PHP version for this project.

Tests

To run the test suite, you first need to clone this repo and then install all dependencies through Composer:

composer install

The test suite contains a number of functional integration tests that send actual test SQL queries against your local database and thus rely on a local MySQL test database with appropriate write access. The test suite creates and modifies a test table in this database, so make sure to not use a production database! You can change your test database credentials by passing these ENV variables:

export DB_HOST=localhost
export DB_PORT=3306
export DB_USER=test
export DB_PASSWD=test
export DB_DBNAME=test

For example, to create an empty test database, you can also use a temporary mysql Docker image like this:

docker run -it --rm --net=host \
    -e MYSQL_RANDOM_ROOT_PASSWORD=yes -e MYSQL_DATABASE=test \
    -e MYSQL_USER=test -e MYSQL_PASSWORD=test mysql:5

To run the test suite, go to the project root and run:

vendor/bin/phpunit

License

MIT, see LICENSE file.

This is a community project now managed by @friends-of-reactphp. The original implementation was created by @bixuehujin starting in 2013 and has been migrated to @friends-of-reactphp in 2018 to help with maintenance and upcoming feature development.

The original implementation was made possible thanks to the following projects: