Linio Database

Linio Database is a component of the Linio Framework. It aims to abstract database access by wrapping PDO and providing helper methods to speed up development.

Install

The recommended way to install Linio Database is through composer.

$ composer require linio/database

Tests

To run the test suite, you need install the dependencies via composer, then run PHPUnit.

$ composer install
$ vendor/bin/phpunit

Usage

<?php

use Linio\Component\Database\DatabaseManager;

$container['db'] = function() {
    $db = new DatabaseManager();
    $driverOptions = [
        'host' => '127.0.0.1',
        'port' => 3306,
        'dbname' => 'test_db',
        'username' => 'root',
        'password' => '',
        'pdo_attributes' => [
            \PDO::ATTR_PERSISTENT => true,
            \PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION,
        ],
    ];
    $db->addConnection(DatabaseManager::DRIVER_MYSQL, $driverOptions);

    return $db;
};

$rows = $container['db']->fetchAll("SELECT * FROM `table` WHERE `field` = :value", ['value' => 'test']);

Roles

For performance reasons, you might want to use slave databases for read queries while sending write queries to the master database. When creating a connection, you can specify the connection role: ROLE_MASTER or ROLE_SLAVE. Only one master connection is allowed.

You can have multiple slave connections. The weight parameter is used to balance the queries among the slaves. Database servers capable of handling more load should have higher weight paramaters.

In order to force a read query to use the master connection, use the parameter forceMasterConnection when using the fetch methods.

Safe Mode

When you use read replicas to improve the performance in your database, in a master-slave setup, the replication lag between the instances may cause some issues when you try to read data that you have recently modified.

The safe mode option guarantees that, once you have used the master connection to issue a query, every query from this moment on will use the same connection for reads.

To prevent replication lag issues, this library uses the safe mode by default. To override this behavior, set the $safeMode parameter to false when instantiating the DatabaseManager object.

<?php

use Linio\Component\Database\DatabaseManager;

$db = new DatabaseManager(false);

Methods

addConnection

<?php

public function addConnection(string $driver, array $options, string $role = DatabaseManager::ROLE_MASTER, int $weight = 1): bool;

$masterDbOptions = ['host' => '127.0.0.1', 'port' => 3306, 'dbname' => 'master_db', 'username' => 'root','password' => ''];
$db->addConnection(DatabaseManager::DRIVER_MYSQL, $masterDbOptions, DatabaseManager::ROLE_MASTER);

$bigSlaveDbOptions = ['host' => '127.0.0.1', 'port' => 3306, 'dbname' => 'big_slave_db', 'username' => 'root','password' => ''];
$db->addConnection(DatabaseManager::DRIVER_MYSQL, $bigSlaveDbOptions, DatabaseManager::ROLE_SLAVE, 5);

$smallSlaveDbOptions = ['host' => '127.0.0.1', 'port' => 3306, 'dbname' => 'small_slave_db', 'username' => 'root','password' => ''];
$db->addConnection(DatabaseManager::DRIVER_MYSQL, $smallSlaveDbOptions, DatabaseManager::ROLE_SLAVE, 2);

getConnections

<?php

use Linio\Component\Database\Entity\Connection;

/**
 * @return Connection[]
 */
public function getConnections() : array;

$connections = $db->getConnections();

var_dump($connections);

/*
array(2) {
  'master' =>
  class Linio\Component\Database\Entity\Connection
  'slave' =>
  array(2) {
    [0] =>
    class Linio\Component\Database\Entity\Connection
    [1] =>
    class Linio\Component\Database\Entity\Connection
  }
}
*/

fetchAll

<?php

use Linio\Component\Database\Exception\FetchException;
use Linio\Component\Database\Exception\InvalidQueryException;

/**
 * @throws InvalidQueryException
 * @throws FetchException
 */
public function fetchAll(string $query, array $params = [], bool $forceMasterConnection = false): array;

$rows = $db->fetchAll("SELECT `id`,`name` FROM `table` WHERE `id` > ?", [1]);

var_dump($rows);

/*
array(2) {
  [0] =>
  array(2) {
    'id' =>
    string(1) "2"
    'name' =>
    string(6) "name 2"
  }
  [1] =>
  array(2) {
    'id' =>
    string(1) "3"
    'name' =>
    string(6) "name 3"
  }
}
*/

fetchOne

<?php

use Linio\Component\Database\Exception\FetchException;
use Linio\Component\Database\Exception\InvalidQueryException;

/**
 * @throws InvalidQueryException
 * @throws FetchException
 */
public function fetchOne(string $query, array $params = [], bool $forceMasterConnection = false): array;

$row = $db->fetchOne("SELECT `id`,`name` FROM `table` WHERE `id` = :id", ['id' => 1]);

var_dump($row);

/*
array(2) {
    'id' =>
    string(1) "1"
    'name' =>
    string(6) "name 1"
}
*/

fetchValue

<?php

use Linio\Component\Database\Exception\FetchException;
use Linio\Component\Database\Exception\InvalidQueryException;

/**
 * @throws InvalidQueryException
 * @throws FetchException
 */
public function fetchValue(string $query, array $params = [], bool $forceMasterConnection = false)

$name = $db->fetchValue("SELECT `name` FROM `table` WHERE `id` = :id", ['id' => 1]);

var_dump($row);

/*
string(6) "name 1"
*/

fetchKeyPairs

<?php

use Linio\Component\Database\Exception\FetchException;
use Linio\Component\Database\Exception\InvalidQueryException;

/**
 * @throws InvalidQueryException
 * @throws FetchException
 */
public function fetchKeyPairs(string $query, array $params = [], bool $forceMasterConnection = false): array;

$keyPairs = $db->fetchKeyPairs("SELECT `id`,`name` FROM `table` WHERE `id` > :id", ['id' => 1]);

var_dump($keyPairs);

/*
array(2) {
    '2' =>
    string(6) "name 2"
    '3' =>
    string(6) "name 3"
}
*/

fetchColumn

<?php

use Linio\Component\Database\Exception\FetchException;
use Linio\Component\Database\Exception\InvalidQueryException;

/**
 * @throws InvalidQueryException
 * @throws FetchException
 */
public function fetchColumn(string $query, array $params = [], int $columnIndex = 0, bool $forceMasterConnection = false): array;

$names = $db->fetchColumn("SELECT `id`,`name` FROM `table` WHERE `id` > :id", ['id' => 1], 1);

var_dump($names);

/*
array(2) {
    [0] =>
    string(6) "name 2"
    [1] =>
    string(6) "name 3"
}
*/

fetchLazy

<?php

use Linio\Component\Database\Entity\LazyFetch;
use Linio\Component\Database\Exception\InvalidQueryException;

/**
 * @throws InvalidQueryException
 */
public function fetchLazy(string $query, array $params = [], bool $forceMasterConnection = false): LazyFetch;

$lazyFetch = $db->fetchLazy("SELECT `id`,`name` FROM `table` WHERE `id` > ?", [1]);

while ($row = $lazyFetch->fetch()) {
    $name = $row['name'];
}

In this example, when this while loop reached the end of the result set, the fetch() method will return an empty array.

execute

<?php

use Linio\Component\Database\Exception\InvalidQueryException;

/**
 * @throws InvalidQueryException
 */
public function execute(string $query, array $params = []): int;

$affectedRowsInsert = $db->execute("INSERT INTO `table` VALUES(:id, :name)", ['id' => 10, 'name' => 'test_name']);

var_dump($affectedRowsInsert);

/*
int(1)
*/

$affectedRowsUpdate = $db->execute("UPDATE `table` SET `name` = :name", ['name' => 'test_name']);

var_dump($affectedRowsUpdate);

/*
int(3)
*/

escapeValue

<?php

use Linio\Component\Database\Exception\DatabaseException;

/**
 * @throws DatabaseException
 */
public function escapeValue(string $value): string;

$escapedValue = $db->escapeValue('Linio\'s Library');

var_dump($escapedValue);

/*
string(17) "Linio\\'s Library"
*/

escapeValues

<?php

use Linio\Component\Database\Exception\DatabaseException;

/**
 * @throws DatabaseException
 */
public function escapeValues(array $values): array;

$escapedValues = $db->escapeValues(['Linio\'s Library', 'Linio\'s Library']);

var_dump($escapedValues);

/*
 * 
array(2) {                    
  [0]=>                       
  string(17) "Linio\\'s Library"
  [1]=>                       
  string(17) "Linio\\'s Library"
}                             
*/

Exceptions

Linio\Component\Database\Exception\DatabaseConnectionException

Reasons:

• Invalid driver name
• Invalid connections parameters
• Error when trying to establish a connection to the database

Linio\Component\Database\Exception\InvalidQueryException

Reasons:

• Lost connection to the database before creating the statement
• Malformed SQL query
• Wrong table or field names

Linio\Component\Database\Exception\FetchException

Reasons:

• Lost connection to the database after creating the statement

Linio\Component\Database\Exception\TransactionException

Reasons:

• Failure to begin, commit or rollback a transaction

Linio\Component\Database\Exception\DatabaseException

Reasons:

• All exceptions extend from this
• Non-specific errors

Drivers

DatabaseManager::MYSQL

Adapter options:

• host string
• port int
• dbname string
• username string
• password string
• pdo_attributes array optional

---

DatabaseManager::PGSQL

Adapter options:

• host string
• port int
• dbname string
• username string
• password string
• pdo_attributes array optional

---

DatabaseManager::SQLITE

Adapter options:

• filepath

---

DatabaseManager::SQLSRV

Adapter options:

• host string
• port int
• dbname string
• username string
• password string
• pdo_attributes array optional

---