PHP database class [IN PROGRESS]

database.php

<?php declare(strict_types = 1);

namespace CMS\Data;
include_once(__DIR__ . '/../helpers/array.php');

/**
*    Database class that handles all database connections and related actions.
*   
*   @param $user        The connecting user
*   @param $pass        Password for the $user
*   @param $database    The database to connect to
*   @param $server      The server the database is on
*/
class Database
{
    private $connection;
    private $userName;
    private $password;
    private $databaseName;    
    private $server;
    private $isConnected;
    private $connectionAttempts;
    private $query;

    public function __construct($user, $pass, $database, $server)
    {
        $this->userName = $user;
        $this->password = $pass;
        $this->databaseName = $database;
        $this->server = $server;
        $this->isConnected = false;
        $this->connectionAttempts = 0;
        $this->query = "";
    }

    /*
        Connects to the database via MySQLi and sets the local $isConnected variable.
    */
    public function connect()
    {
        if (!$this->isConnected)
        {
            $this->connection = new \mysqli($this->server, $this->userName, $this->password, $this->databaseName);

            if ($this->connection->connect_errno) 
            {
                if ($this->connectionAttempts < 2)
                {
                    $this->reconnect();
                }
                else
                {
                    echo "Sorry, something went wrong with your connection.\n";
                    echo "Error: Failed to make a MySQL connection to the database: <strong>$this->databaseName</strong>\n";
                    echo "Errno: $this->connection->connect_errno\n";
                    echo "Error: $this->connection->connect_error";
                    exit;
                }
            }

            $this->isConnected = true;
        }
    }

    /**
    *   Runs a SELECT query and returns the class object for chaining.
    *
    *   @param $table       A string of the table name
    *   @param $columns     An array of column names or a string value ('*', 'name', etc.)
    */
    public function select($table, $columns)
    {
        $this->query = "SELECT ";
        
        if (\is_array($columns))
        {
            $index = 0;
            $columnCount = \count($columns);

            foreach ($columns as $c)
            {
                $this->query .= $c;
                
                if (++$index != $columnCount)
                {
                    $this->query .= ", ";
                }
                else
                {
                    $this->query .= " ";
                }
            }
        }
        elseif (\is_string($columns))
        {
            $this->query .= $columns;
        }
        else
        {
            $this->query .= $columns . " ";
        }

        $this->query .= "FROM `" . \ucfirst($table) . "`";
        return $this;
    }

    /**
    *   Chains a WHERE clause onto a another chainable query and returns the class object for chaining.
    *
    *   @param $column      A string of the column name
    *   @param $comparison  A string of the comparison operator (like, =, etc.)
    *   @param $value       A numeric or string value
    */
    public function where($column, $comparison, $value)
    {
        $this->query .= " WHERE $column ";

        if (\is_string($value))
        {
            if ($comparison == "like")
            {
                $this->query .= strtoupper($comparison) . " '%$value%'";
            }
            else
            {
                $this->query .= "$comparison '$value'";
            }
        }
        else
        {
            $this->query .= $comparison . " " . $value;
        }

        return $this;
    }

    /**
    *   Runs an insert query and returns a boolean value.
    *
    *   @param $table       A string of the table name
    *   @param $columns     An array of the columns names
    *   @param $values      An array of the inserted values
    */
    public function insert($table, $columns, $values)
    {
        $numColumns = \count($columns);
        $numValues = \count($values);
        $index = 0;

        $query = "INSERT INTO `$table` ";
        $query .= "(";

        foreach ($columns as $c)
        {
            $query .= $c;

            if (++$index !== $numColumns)
            {
                $query .= ", ";
            }
        }

        $index = 0;
        $query .= ") VALUES (";

        foreach ($values as $v)
        {
            if (\is_string($v))
            {
                $query .= "'$v'";
            }
            else
            {
                $query .= $v;
            }

            if (++$index !== $numValues)
            {
                $query .= ", ";
            }
        }

        $query .= ")";

        return $this->connection->query($query);
    }

    /**
    *   Runs an UPDATE statement and returns the class object for chaining.
    *
    *   @param $table   A string of the table name
    *   @param $column  A string of the column name
    *   @param $value   A numeric or string value
    */
    public function update($table, $column, $value)
    {
        $this->query = "UPDATE `". \ucfirst($table) . "` SET $column = ";

        if (\is_string($value))
        {
            $this->query .= "'$value'";
        }
        else
        {
            $this->query .= $value;
        }

        return $this;        
    }

    /**
    *   Runs a DELETE statement and returns the class object for chaining.
    *
    *   @param $table   A string of the table name
    */
    public function delete($table)
    {
        $this->query = "DELETE FROM `" . \ucfirst($table) . "`";
        return $this;
    }

    /*
        Runs a the class' built SQL query and returns the result.
    */
    public function result()
    {
        $result = $this->connection->query($this->query);

        if (!\is_bool($result))
        {
            $sqlResult = $result->fetch_assoc();
            $result->free();
            return $sqlResult;
        }
        else
        {
            $sqlResult = $result;
            $result->free();
            return $result;
        }

        $this->connection->close();
    }

    /* 
        Returns if there is a connection to the database
    */
    public function isConnected()
    {
        return $this->isConnected;
    }
    
    /*
        Attempts to reconnect to the database if the initial 3 connections fail.
    */
    private function reconnect()
    {
        if ($this->connectionAttempts < 2)
        {
            $this->connectionAttempts++;
            $this->connect();
        }
        else
        {
            die("Cannot connect to database: <strong>$this->databaseName</strong>. Please check your connection information.");
        }
    }
}

usage.php

<?php declare(strict_types = 1);
require(__DIR__ . '/../data/database.php');

$db = new CMS\Data\Database('bradyng', '', 'PHPCms', 'localhost');
$db->connect();

$table = 'user';
$column = '*';

$results = $db->select($table, $column)->where('username', 'like', 'jo')->result();
print_r($results);