Subreality\Dilmun\Enki\MySql

Complexity

Total Complexity

16

Size/Duplication

Total Lines	168
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	1

Test Coverage

Coverage

100%

Importance

Changes	3
Bugs	0	Features	0

5 Methods

Rating	Name	Duplication	Size	Complexity
A	connect()	0	21	2
A	disconnect()	0	12	2
B	getPrimaryKeys()	0	32	5
B	getRowById()	0	33	5
A	tableExists()	0	16	2

<?php

namespace Subreality\Dilmun\Enki;

use Subreality\Dilmun\LoggedClassTrait;

/**
 * Class MySql
 * @package Subreality\Dilmun\Enki
 */
class MySql implements EnkiInterface
{
    use LoggedClassTrait;

    /**
     * @var \PDO
     */
    private $pdo;

    /**
     * Provides a MySQL connection interface that catches a PDOException on failure.
     *
     * @param string $host  The host name for the MySQL connection
     * @param string $user  The username for the MySQL connection
     * @param string $pass  The password for the MySQL connection
     * @param string $name  The database name for the MySQL connection
     *
     * @return bool         Returns true if the connection was successful; returns false otherwise
     */
    public function connect($host, $user, $pass, $name)
    {
        $dsn = "mysql:host={$host};dbname={$name}";

        try {
            $this->pdo = new \PDO($dsn, $user, $pass);
            $this->pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);

            $connected = true;
        } catch (\PDOException $pdo_e) {
            $context = array();
            
            $context["exception"] = $pdo_e;

            $this->updateLog("error", "MySQL connection failed with the following message: {message}", $context);
            
            $connected = false;
        }

        return $connected;
    }

    /**
     * Destroys an existing PDO connection
     *
     * @return bool Returns true if the connection existed and was destroyed; returns false otherwise
     */
    public function disconnect()
    {
        if ($this->pdo instanceof \PDO) {
            $this->pdo = null;

            $disconnected = true;
        } else {
            $disconnected = false;
        }

        return $disconnected;
    }

    /**
     * Gets the column names for all primary keys for a table or returns false if no keys exist
     *
     * @param string $table The table from which keys will be retrieved
     *
     * @return mixed        Returns an array of column names if the table has a compound primary key;
     *                      returns a single column name if the table has only one primary key;
     *                      returns false if the table has no primary keys
     */
    public function getPrimaryKeys($table)
    {
        $table_exists = $this->tableExists($table);

        if ($table_exists) {
            $keys_query = "SHOW KEYS FROM {$table} WHERE Key_name='PRIMARY'";

            $statement = $this->pdo->prepare($keys_query);

            $statement->execute();

            $result = $statement->fetchAll();

            $row_count = $statement->rowCount();

            if ($row_count > 1) {
                $keys = array();

                foreach ($result as $row) {
                    $keys[] = $row['Column_name'];
                }
            } elseif ($row_count == 1) {
                $keys = $result[0]['Column_name'];
            } else {
                $keys = false;
            }
        } else {
            $keys = false;
        }

        return $keys;
    }

    /**
     * Retrieves a row represented by a single primary key
     *
     * @param int|string $id    A unique id for a table
     * @param string $table     The table from which a row will be retrieved
     *
     * @return array|false      Returns an associative array representing the row corresponding with the primary key;
     *                          returns false if the table does not exist, if the provided id does not correspond with a
     *                          record, or if the table has a compound primary key
     */
    public function getRowById($id, $table)
    {
        $key = $this->getPrimaryKeys($table);

        if (is_string($id)) {
            $query_id = "'{$id}'";
        } else {
            $query_id = $id;
        }

        if ($key === false) {
            $row = false;
        } elseif (is_array($key)) {
            $row = false;
        } else {
            $query = "SELECT * FROM {$table}
                        WHERE {$key} = {$query_id}";

            $statement = $this->pdo->prepare($query);

            $statement->execute();

            $result = $statement->fetchAll(\PDO::FETCH_ASSOC);

            if (empty($result)) {
                $row = false;
            } else {
                $row = $result[0];
            }
        }

        return $row;
    }

    /**
     * Determines whether a given table exists
     *
     * @param string $table The table that will be checked for existence
     * @return bool         Returns true if the table exists; returns false otherwise
     */
    public function tableExists($table)
    {
        $table_query = "SHOW TABLES LIKE '{$table}'";

        $statement = $this->pdo->prepare($table_query);

        $statement->execute();

        $row_count = $statement->rowCount();

        if ($row_count == 0) {

The if-else statement can be simplified to return !($row_count == 0);.

            return false;
        } else {
            return true;
        }
    }
}