Database_Core

Complexity

Total Complexity

199

Size/Duplication

Total Lines	1326
Duplicated Lines	19.46 %

Coupling/Cohesion

Components	1
Dependencies	3

Importance

Changes	3
Bugs	2	Features	0

52 Methods

Rating	Name	Duplication	Size	Complexity
A	instance()	9	9	3
A	instance_name()	0	4	1
D	__construct()	3	108	16
B	connect()	0	13	5
C	query()	0	35	7
D	select()	7	33	10
C	from()	28	34	7
D	join()	17	60	12
B	where()	18	18	7
B	orwhere()	18	18	7
A	like()	11	11	4
A	orlike()	11	11	4
A	notlike()	11	11	4
A	ornotlike()	11	11	4
A	regex()	11	11	4
A	orregex()	11	11	4
A	notregex()	11	11	4
A	ornotregex()	11	11	4
B	groupby()	12	21	5
A	having()	0	5	1
A	orhaving()	0	5	1
B	orderby()	0	24	5
A	limit()	0	10	3
A	offset()	0	6	1
A	set()	8	17	4
A	get()	0	20	3
B	getwhere()	0	22	4
A	compile()	0	16	3
B	insert()	0	27	6
B	in()	0	19	6
A	notin()	0	4	1
B	merge()	23	23	5
B	update()	27	27	6
B	delete()	0	25	5
A	last_query()	0	4	1
A	count_records()	0	18	4
A	reset_select()	0	13	1
A	reset_write()	0	6	1
A	list_tables()	0	6	2
A	table_exists()	0	8	2
A	compile_binds()	0	21	3
A	field_data()	0	6	2
A	list_fields()	0	6	2
A	escape()	0	4	1
A	escape_str()	0	4	1
A	escape_table()	0	4	1
A	escape_column()	0	4	1
A	table_prefix()	0	4	1
A	clear_cache()	0	12	3
A	push()	0	20	1
A	pop()	0	23	2
B	count_last_query()	0	25	4

<?php defined('SYSPATH') or die('No direct access allowed.');
/**
 * Provides database access in a platform agnostic way, using simple query building blocks.
 *
 * $Id: Database.php 4342 2009-05-08 16:56:01Z jheathco $
 *
 * @package    Core
 * @author     Kohana Team
 * @copyright  (c) 2007-2008 Kohana Team
 * @license    http://kohanaphp.com/license.html
 */
class Database_Core
{

    // Database instances
    public static $instances = array();

    // Global benchmark
    public static $benchmarks = array();

    // Configuration
    protected $config = array(
        'benchmark'     => true,
        'persistent'    => false,
        'connection'    => '',
        'character_set' => 'utf8',
        'table_prefix'  => '',
        'object'        => true,
        'cache'         => false,
        'escape'        => true,
    );

    // Database driver object
    protected $driver;
    protected $link;

    // Un-compiled parts of the SQL query
    protected $select     = array();
    protected $set        = array();
    protected $from       = array();
    protected $join       = array();
    protected $where      = array();
    protected $orderby    = array();
    protected $order      = array();
    protected $groupby    = array();
    protected $having     = array();
    protected $distinct   = false;
    protected $limit      = false;
    protected $offset     = false;
    protected $last_query = '';

    // Stack of queries for push/pop
    protected $query_history = array();

    /**
     * Returns a singleton instance of Database.
     *
     * @param   mixed   configuration array or DSN
     * @return  Database_Core
     */
    public static function & instance($name = 'default', $config = null)

This method seems to be duplicated in your project.

    {
        if (! isset(Database::$instances[$name])) {
            // Create a new instance
            Database::$instances[$name] = new Database($config === null ? $name : $config);
        }

        return Database::$instances[$name];
    }

    /**
     * Returns the name of a given database instance.
     *
     * @param   Database  instance of Database
     * @return  string
     */
    public static function instance_name(Database $db)

Avoid variables with short names like $db. Configured minimum length is 3.

    {
        return array_search($db, Database::$instances, true);
    }

    /**
     * Sets up the database configuration, loads the Database_Driver.
     *
     * @throws  Kohana_Database_Exception
     */
    public function __construct($config = array())
    {
        if (empty($config)) {
            // Load the default group
            $config = Kohana::config('database.default');
        } elseif (is_array($config) and count($config) > 0) {
            if (! array_key_exists('connection', $config)) {
                $config = array('connection' => $config);
            }
        } elseif (is_string($config)) {
            // The config is a DSN string
            if (strpos($config, '://') !== false) {
                $config = array('connection' => $config);
            }
            // The config is a group name
            else {
                $name = $config;

                // Test the config group name
                if (($config = Kohana::config('database.'.$config)) === null) {
                    throw new Kohana_Database_Exception('database.undefined_group', $name);
                }
            }
        }

        // Merge the default config with the passed config
        $this->config = array_merge($this->config, $config);

        if (is_string($this->config['connection'])) {
            // Make sure the connection is valid
            if (strpos($this->config['connection'], '://') === false) {
                throw new Kohana_Database_Exception('database.invalid_dsn', $this->config['connection']);
            }

            // Parse the DSN, creating an array to hold the connection parameters
            $db = array(

Avoid variables with short names like $db. Configured minimum length is 3.

                'type'     => false,
                'user'     => false,
                'pass'     => false,
                'host'     => false,
                'port'     => false,
                'socket'   => false,
                'database' => false
            );

            // Get the protocol and arguments
            list($db['type'], $connection) = explode('://', $this->config['connection'], 2);

            if (strpos($connection, '@') !== false) {
                // Get the username and password
                list($db['pass'], $connection) = explode('@', $connection, 2);
                // Check if a password is supplied
                $logindata = explode(':', $db['pass'], 2);
                $db['pass'] = (count($logindata) > 1) ? $logindata[1] : '';
                $db['user'] = $logindata[0];

                // Prepare for finding the database
                $connection = explode('/', $connection);

                // Find the database name
                $db['database'] = array_pop($connection);

                // Reset connection string
                $connection = implode('/', $connection);

                // Find the socket
                if (preg_match('/^unix\([^)]++\)/', $connection)) {
                    // This one is a little hairy: we explode based on the end of
                    // the socket, removing the 'unix(' from the connection string
                    list($db['socket'], $connection) = explode(')', substr($connection, 5), 2);

The assignment to $connection is unused. Consider omitting it like so list($first,,$third).

                } elseif (strpos($connection, ':') !== false) {
                    // Fetch the host and port name
                    list($db['host'], $db['port']) = explode(':', $connection, 2);
                } else {
                    $db['host'] = $connection;
                }
            } else {
                // File connection
                $connection = explode('/', $connection);

                // Find database file name
                $db['database'] = array_pop($connection);

                // Find database directory name
                $db['socket'] = implode('/', $connection).'/';
            }

            // Reset the connection array to the database config
            $this->config['connection'] = $db;
        }
        // Set driver name
        $driver = 'Database_'.ucfirst($this->config['connection']['type']).'_Driver';

        // Load the driver
        if (! Kohana::auto_load($driver)) {

This code seems to be duplicated across your project.

            throw new Kohana_Database_Exception('core.driver_not_found', $this->config['connection']['type'], get_class($this));
        }

        // Initialize the driver
        $this->driver = new $driver($this->config);

        // Validate the driver
        if (! ($this->driver instanceof Database_Driver)) {
            throw new Kohana_Database_Exception('core.driver_implements', $this->config['connection']['type'], get_class($this), 'Database_Driver');
        }

        Kohana::log('debug', 'Database Library initialized');
    }

    /**
     * Simple connect method to get the database queries up and running.
     *
     * @return  void
     */
    public function connect()
    {
        // A link can be a resource or an object
        if (! is_resource($this->link) and ! is_object($this->link)) {
            $this->link = $this->driver->connect();
            if (! is_resource($this->link) and ! is_object($this->link)) {
                throw new Kohana_Database_Exception('database.connection', $this->driver->show_error());
            }

            // Clear password after successful connect
            $this->config['connection']['pass'] = null;
        }
    }

    /**
     * Runs a query into the driver and returns the result.
     *
     * @param   string  SQL query to execute
     * @return  Database_Result
     */
    public function query($sql = '')
    {
        if ($sql == '') {
            return false;

The return type of return false; (false) is incompatible with the return type documented by Database_Core::query of type Database_Result.

        }

        // No link? Connect!
        $this->link or $this->connect();

        // Start the benchmark
        $start = microtime(true);

        if (func_num_args() > 1) { //if we have more than one argument ($sql)
            $argv = func_get_args();
            $binds = (is_array(next($argv))) ? current($argv) : array_slice($argv, 1);
        }

        // Compile binds if needed
        if (isset($binds)) {
            $sql = $this->compile_binds($sql, $binds);
        }

        // Fetch the result
        $result = $this->driver->query($this->last_query = $sql);

        // Stop the benchmark
        $stop = microtime(true);

        if ($this->config['benchmark'] == true) {
            // Benchmark the query
            Database::$benchmarks[] = array('query' => $sql, 'time' => $stop - $start, 'rows' => count($result));
        }

        return $result;
    }

    /**
     * Selects the column names for a database query.
     *
     * @param   string  string or array of column names to select
     * @return  Database_Core  This Database object.
     */
    public function select($sql = '*')
    {
        if (func_num_args() > 1) {

This code seems to be duplicated across your project.

            $sql = func_get_args();
        } elseif (is_string($sql)) {
            $sql = explode(',', $sql);
        } else {
            $sql = (array) $sql;
        }

        foreach ($sql as $val) {
            if (($val = trim($val)) === '') {
                continue;
            }

            if (strpos($val, '(') === false and $val !== '*') {
                if (preg_match('/^DISTINCT\s++(.+)$/i', $val, $matches)) {
                    // Only prepend with table prefix if table name is specified
                    $val = (strpos($matches[1], '.') !== false) ? $this->config['table_prefix'].$matches[1] : $matches[1];

                    $this->distinct = true;
                } else {
                    $val = (strpos($val, '.') !== false) ? $this->config['table_prefix'].$val : $val;
                }

                $val = $this->driver->escape_column($val);
            }

            $this->select[] = $val;
        }

        return $this;
    }

    /**
     * Selects the from table(s) for a database query.
     *
     * @param   string  string or array of tables to select
     * @param string|boolean $sql
     * @return  Database_Core  This Database object.
     */
    public function from($sql)
    {
        if (func_num_args() > 1) {

This code seems to be duplicated across your project.

            $sql = func_get_args();
        } elseif (is_string($sql)) {
            $sql = explode(',', $sql);
        } else {
            $sql = array($sql);
        }

        foreach ($sql as $val) {

This code seems to be duplicated across your project.

            if (is_string($val)) {
                if (($val = trim($val)) === '') {
                    continue;
                }

                // TODO: Temporary solution, this should be moved to database driver (AS is checked for twice)
                if (stripos($val, ' AS ') !== false) {
                    $val = str_ireplace(' AS ', ' AS ', $val);

                    list($table, $alias) = explode(' AS ', $val);

                    // Attach prefix to both sides of the AS
                    $val = $this->config['table_prefix'].$table.' AS '.$this->config['table_prefix'].$alias;
                } else {
                    $val = $this->config['table_prefix'].$val;
                }
            }

            $this->from[] = $val;
        }

        return $this;
    }

    /**
     * Generates the JOIN portion of the query.
     *
     * @param   string        table name
     * @param   string|array  where key or array of key => value pairs
     * @param   string        where value
     * @param   string        type of join
     * @return  Database_Core        This Database object.
     */
    public function join($table, $key, $value = null, $type = '')
    {
        $join = array();

        if (! empty($type)) {
            $type = strtoupper(trim($type));

            if (! in_array($type, array('LEFT', 'RIGHT', 'OUTER', 'INNER', 'LEFT OUTER', 'RIGHT OUTER'), true)) {
                $type = '';
            } else {
                $type .= ' ';
            }
        }

        $cond = array();
        $keys  = is_array($key) ? $key : array($key => $value);
        foreach ($keys as $key => $value) {
            $key    = (strpos($key, '.') !== false) ? $this->config['table_prefix'].$key : $key;

            if (is_string($value)) {
                // Only escape if it's a string
                $value = $this->driver->escape_column($this->config['table_prefix'].$value);
            }

            $cond[] = $this->driver->where($key, $value, 'AND ', count($cond), false);
        }

        if (! is_array($this->join)) {
            $this->join = array();
        }

        if (! is_array($table)) {
            $table = array($table);
        }

        foreach ($table as $t) {

This code seems to be duplicated across your project.

            if (is_string($t)) {
                // TODO: Temporary solution, this should be moved to database driver (AS is checked for twice)
                if (stripos($t, ' AS ') !== false) {
                    $t = str_ireplace(' AS ', ' AS ', $t);

                    list($table, $alias) = explode(' AS ', $t);

                    // Attach prefix to both sides of the AS
                    $t = $this->config['table_prefix'].$table.' AS '.$this->config['table_prefix'].$alias;
                } else {
                    $t = $this->config['table_prefix'].$t;
                }
            }

            $join['tables'][] = $this->driver->escape_column($t);
        }

        $join['conditions'] = '('.trim(implode(' ', $cond)).')';
        $join['type'] = $type;

        $this->join[] = $join;

        return $this;
    }


    /**
     * Selects the where(s) for a database query.
     *
     * @param   string|array  key name or array of key => value pairs
     * @param   string        value to match with key
     * @param   boolean       disable quoting of WHERE clause
     * @return  Database_Core        This Database object.
     */
    public function where($key, $value = null, $quote = true)

This method seems to be duplicated in your project.

    {
        $quote = (func_num_args() < 2 and ! is_array($key)) ? -1 : $quote;
        if (is_object($key)) {
            $keys = array((string) $key => '');
        } elseif (! is_array($key)) {
            $keys = array($key => $value);
        } else {
            $keys = $key;
        }

        foreach ($keys as $key => $value) {
            $key           = (strpos($key, '.') !== false) ? $this->config['table_prefix'].$key : $key;
            $this->where[] = $this->driver->where($key, $value, 'AND ', count($this->where), $quote);
        }

        return $this;
    }

    /**
     * Selects the or where(s) for a database query.
     *
     * @param   string|array  key name or array of key => value pairs
     * @param   string        value to match with key
     * @param   boolean       disable quoting of WHERE clause
     * @return  Database_Core        This Database object.
     */
    public function orwhere($key, $value = null, $quote = true)

This method seems to be duplicated in your project.

    {
        $quote = (func_num_args() < 2 and ! is_array($key)) ? -1 : $quote;
        if (is_object($key)) {
            $keys = array((string) $key => '');
        } elseif (! is_array($key)) {
            $keys = array($key => $value);
        } else {
            $keys = $key;
        }

        foreach ($keys as $key => $value) {
            $key           = (strpos($key, '.') !== false) ? $this->config['table_prefix'].$key : $key;
            $this->where[] = $this->driver->where($key, $value, 'OR ', count($this->where), $quote);
        }

        return $this;
    }

    /**
     * Selects the like(s) for a database query.
     *
     * @param   string|array  field name or array of field => match pairs
     * @param   string        like value to match with field
     * @param   boolean       automatically add starting and ending wildcards
     * @return  Database_Core        This Database object.
     */
    public function like($field, $match = '', $auto = true)

This method seems to be duplicated in your project.

    {
        $fields = is_array($field) ? $field : array($field => $match);

        foreach ($fields as $field => $match) {
            $field         = (strpos($field, '.') !== false) ? $this->config['table_prefix'].$field : $field;
            $this->where[] = $this->driver->like($field, $match, $auto, 'AND ', count($this->where));
        }

        return $this;
    }

    /**
     * Selects the or like(s) for a database query.
     *
     * @param   string|array  field name or array of field => match pairs
     * @param   string        like value to match with field
     * @param   boolean       automatically add starting and ending wildcards
     * @return  Database_Core        This Database object.
     */
    public function orlike($field, $match = '', $auto = true)

This method seems to be duplicated in your project.

    {
        $fields = is_array($field) ? $field : array($field => $match);

        foreach ($fields as $field => $match) {
            $field         = (strpos($field, '.') !== false) ? $this->config['table_prefix'].$field : $field;
            $this->where[] = $this->driver->like($field, $match, $auto, 'OR ', count($this->where));
        }

        return $this;
    }

    /**
     * Selects the not like(s) for a database query.
     *
     * @param   string|array  field name or array of field => match pairs
     * @param   string        like value to match with field
     * @param   boolean       automatically add starting and ending wildcards
     * @return  Database_Core        This Database object.
     */
    public function notlike($field, $match = '', $auto = true)

This method seems to be duplicated in your project.

    {
        $fields = is_array($field) ? $field : array($field => $match);

        foreach ($fields as $field => $match) {
            $field         = (strpos($field, '.') !== false) ? $this->config['table_prefix'].$field : $field;
            $this->where[] = $this->driver->notlike($field, $match, $auto, 'AND ', count($this->where));
        }

        return $this;
    }

    /**
     * Selects the or not like(s) for a database query.
     *
     * @param   string|array  field name or array of field => match pairs
     * @param   string        like value to match with field
     * @return  Database_Core        This Database object.
     */
    public function ornotlike($field, $match = '', $auto = true)

This method seems to be duplicated in your project.

    {
        $fields = is_array($field) ? $field : array($field => $match);

        foreach ($fields as $field => $match) {
            $field         = (strpos($field, '.') !== false) ? $this->config['table_prefix'].$field : $field;
            $this->where[] = $this->driver->notlike($field, $match, $auto, 'OR ', count($this->where));
        }

        return $this;
    }

    /**
     * Selects the like(s) for a database query.
     *
     * @param   string|array  field name or array of field => match pairs
     * @param   string        like value to match with field
     * @return  Database_Core        This Database object.
     */
    public function regex($field, $match = '')

This method seems to be duplicated in your project.

    {
        $fields = is_array($field) ? $field : array($field => $match);

        foreach ($fields as $field => $match) {
            $field         = (strpos($field, '.') !== false) ? $this->config['table_prefix'].$field : $field;
            $this->where[] = $this->driver->regex($field, $match, 'AND ', count($this->where));
        }

        return $this;
    }

    /**
     * Selects the or like(s) for a database query.
     *
     * @param   string|array  field name or array of field => match pairs
     * @param   string        like value to match with field
     * @return  Database_Core        This Database object.
     */
    public function orregex($field, $match = '')

This method seems to be duplicated in your project.

    {
        $fields = is_array($field) ? $field : array($field => $match);

        foreach ($fields as $field => $match) {
            $field         = (strpos($field, '.') !== false) ? $this->config['table_prefix'].$field : $field;
            $this->where[] = $this->driver->regex($field, $match, 'OR ', count($this->where));
        }

        return $this;
    }

    /**
     * Selects the not regex(s) for a database query.
     *
     * @param   string|array  field name or array of field => match pairs
     * @param   string        regex value to match with field
     * @return  Database_Core        This Database object.
     */
    public function notregex($field, $match = '')

This method seems to be duplicated in your project.

    {
        $fields = is_array($field) ? $field : array($field => $match);

        foreach ($fields as $field => $match) {
            $field         = (strpos($field, '.') !== false) ? $this->config['table_prefix'].$field : $field;
            $this->where[] = $this->driver->notregex($field, $match, 'AND ', count($this->where));
        }

        return $this;
    }

    /**
     * Selects the or not regex(s) for a database query.
     *
     * @param   string|array  field name or array of field => match pairs
     * @param   string        regex value to match with field
     * @return  Database_Core        This Database object.
     */
    public function ornotregex($field, $match = '')

This method seems to be duplicated in your project.

    {
        $fields = is_array($field) ? $field : array($field => $match);

        foreach ($fields as $field => $match) {
            $field         = (strpos($field, '.') !== false) ? $this->config['table_prefix'].$field : $field;
            $this->where[] = $this->driver->notregex($field, $match, 'OR ', count($this->where));
        }

        return $this;
    }

    /**
     * Chooses the column to group by in a select query.
     *
     * @param   string  column name to group by
     * @return  Database_Core  This Database object.
     */
    public function groupby($by)

Avoid variables with short names like $by. Configured minimum length is 3.

    {
        if (! is_array($by)) {
            $by = explode(',', (string) $by);
        }

        foreach ($by as $val) {

This code seems to be duplicated across your project.

            $val = trim($val);

            if ($val != '') {
                // Add the table prefix if we are using table.column names
                if (strpos($val, '.')) {
                    $val = $this->config['table_prefix'].$val;
                }

                $this->groupby[] = $this->driver->escape_column($val);
            }
        }

        return $this;
    }

    /**
     * Selects the having(s) for a database query.
     *
     * @param   string|array  key name or array of key => value pairs
     * @param   string        value to match with key
     * @param   boolean       disable quoting of WHERE clause
     * @return  Database_Core        This Database object.
     */
    public function having($key, $value = '', $quote = true)

The parameter $quote is not used and could be removed.

    {
        $this->having[] = $this->driver->where($key, $value, 'AND', count($this->having), true);
        return $this;
    }

    /**
     * Selects the or having(s) for a database query.
     *
     * @param   string|array  key name or array of key => value pairs
     * @param   string        value to match with key
     * @param   boolean       disable quoting of WHERE clause
     * @return  Database_Core        This Database object.
     */
    public function orhaving($key, $value = '', $quote = true)

The parameter $quote is not used and could be removed.

    {
        $this->having[] = $this->driver->where($key, $value, 'OR', count($this->having), true);
        return $this;
    }

    /**
     * Chooses which column(s) to order the select query by.
     *
     * @param   string|array  column(s) to order on, can be an array, single column, or comma seperated list of columns
     * @param   string        direction of the order
     * @return  Database_Core        This Database object.
     */
    public function orderby($orderby, $direction = null)
    {
        if (! is_array($orderby)) {
            $orderby = array($orderby => $direction);
        }

        foreach ($orderby as $column => $direction) {
            $direction = strtoupper(trim($direction));

            // Add a direction if the provided one isn't valid
            if (! in_array($direction, array('ASC', 'DESC', 'RAND()', 'RANDOM()', 'NULL'))) {
                $direction = 'ASC';
            }

            // Add the table prefix if a table.column was passed
            if (strpos($column, '.')) {
                $column = $this->config['table_prefix'].$column;
            }

            $this->orderby[] = $this->driver->escape_column($column).' '.$direction;
        }

        return $this;
    }

    /**
     * Selects the limit section of a query.
     *
     * @param   integer  number of rows to limit result to
     * @param   integer  offset in result to start returning rows from
     * @return  Database_Core   This Database object.
     */
    public function limit($limit, $offset = null)
    {
        $this->limit  = (int) $limit;

The property $limit was declared of type boolean, but (int) $limit is of type integer. Maybe add a type cast?

        if ($offset !== null or ! is_int($this->offset)) {
            $this->offset($offset);
        }

        return $this;
    }

    /**
     * Sets the offset portion of a query.
     *
     * @param   integer  offset value
     * @return  Database_Core   This Database object.
     */
    public function offset($value)
    {
        $this->offset = (int) $value;

The property $offset was declared of type boolean, but (int) $value is of type integer. Maybe add a type cast?

        return $this;
    }

    /**
     * Allows key/value pairs to be set for inserting or updating.
     *
     * @param   string|array  key name or array of key => value pairs
     * @param   string        value to match with key
     * @return  Database_Core        This Database object.
     */
    public function set($key, $value = '')
    {
        if (! is_array($key)) {
            $key = array($key => $value);
        }

        foreach ($key as $k => $v) {

This code seems to be duplicated across your project.

            // Add a table prefix if the column includes the table.
            if (strpos($k, '.')) {
                $k = $this->config['table_prefix'].$k;
            }

            $this->set[$k] = $this->driver->escape($v);
        }

        return $this;
    }

    /**
     * Compiles the select statement based on the other functions called and runs the query.
     *
     * @param   string  table name
     * @param   string  limit clause
     * @param   string  offset clause
     * @return  Database_Result
     */
    public function get($table = '', $limit = null, $offset = null)
    {
        if ($table != '') {
            $this->from($table);
        }

        if (! is_null($limit)) {
            $this->limit($limit, $offset);
        }

        $sql = $this->driver->compile_select(get_object_vars($this));

        $this->reset_select();

        $result = $this->query($sql);

        $this->last_query = $sql;

        return $result;
    }

    /**
     * Compiles the select statement based on the other functions called and runs the query.
     *
     * @param   string  table name
     * @param   array   where clause
     * @param   string  limit clause
     * @param   string  offset clause
     * @return  Database_Result  This Database object.
     */
    public function getwhere($table = '', $where = null, $limit = null, $offset = null)
    {
        if ($table != '') {
            $this->from($table);
        }

        if (! is_null($where)) {
            $this->where($where);
        }

        if (! is_null($limit)) {
            $this->limit($limit, $offset);
        }

        $sql = $this->driver->compile_select(get_object_vars($this));

        $this->reset_select();

        $result = $this->query($sql);

        return $result;
    }

    /**
     * Compiles the select statement based on the other functions called and returns the query string.
     *
     * @param   string  table name
     * @param   string  limit clause
     * @param   string  offset clause
     * @return  string  sql string
     */
    public function compile($table = '', $limit = null, $offset = null)
    {
        if ($table != '') {
            $this->from($table);
        }

        if (! is_null($limit)) {
            $this->limit($limit, $offset);
        }

        $sql = $this->driver->compile_select(get_object_vars($this));

        $this->reset_select();

        return $sql;
    }

    /**
     * Compiles an insert string and runs the query.
     *
     * @param   string  table name
     * @param   array   array of key/value pairs to insert
     * @return  Database_Result  Query result
     */
    public function insert($table = '', $set = null)
    {
        if (! is_null($set)) {
            $this->set($set);
        }

        if ($this->set == null) {
            throw new Kohana_Database_Exception('database.must_use_set');
        }

        if ($table == '') {
            if (! isset($this->from[0])) {
                throw new Kohana_Database_Exception('database.must_use_table');
            }

            $table = $this->from[0];
        }

        // If caching is enabled, clear the cache before inserting
        ($this->config['cache'] === true) and $this->clear_cache();

        $sql = $this->driver->insert($this->config['table_prefix'].$table, array_keys($this->set), array_values($this->set));

        $this->reset_write();

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

    /**
     * Adds an "IN" condition to the where clause
     *
     * @param   string  Name of the column being examined
     * @param   mixed   An array or string to match against
     * @param   bool    Generate a NOT IN clause instead
     * @return  Database_Core  This Database object.
     */
    public function in($field, $values, $not = false)

This method's name is shorter than the configured minimum length of 3 characters.

    {
        if (is_array($values)) {
            $escaped_values = array();
            foreach ($values as $v) {
                if (is_numeric($v)) {
                    $escaped_values[] = $v;
                } else {
                    $escaped_values[] = "'".$this->driver->escape_str($v)."'";
                }
            }
            $values = implode(",", $escaped_values);
        }

        $where = $this->driver->escape_column(((strpos($field, '.') !== false) ? $this->config['table_prefix'] : ''). $field).' '.($not === true ? 'NOT ' : '').'IN ('.$values.')';
        $this->where[] = $this->driver->where($where, '', 'AND ', count($this->where), -1);

        return $this;
    }

    /**
     * Adds a "NOT IN" condition to the where clause
     *
     * @param   string  Name of the column being examined
     * @param   mixed   An array or string to match against
     * @return  Database_Core  This Database object.
     */
    public function notin($field, $values)
    {
        return $this->in($field, $values, true);
    }

    /**
     * Compiles a merge string and runs the query.
     *
     * @param   string  table name
     * @param   array   array of key/value pairs to merge
     * @return  Database_Result  Query result
     */
    public function merge($table = '', $set = null)

This method seems to be duplicated in your project.

    {
        if (! is_null($set)) {
            $this->set($set);
        }

        if ($this->set == null) {
            throw new Kohana_Database_Exception('database.must_use_set');
        }

        if ($table == '') {
            if (! isset($this->from[0])) {
                throw new Kohana_Database_Exception('database.must_use_table');
            }

            $table = $this->from[0];
        }

        $sql = $this->driver->merge($this->config['table_prefix'].$table, array_keys($this->set), array_values($this->set));

        $this->reset_write();
        return $this->query($sql);
    }

    /**
     * Compiles an update string and runs the query.
     *
     * @param   string  table name
     * @param   array   associative array of update values
     * @param   array   where clause
     * @return  Database_Result  Query result
     */
    public function update($table = '', $set = null, $where = null)

This method seems to be duplicated in your project.

    {
        if (is_array($set)) {
            $this->set($set);
        }

        if (! is_null($where)) {
            $this->where($where);
        }

        if ($this->set == false) {
            throw new Kohana_Database_Exception('database.must_use_set');
        }

        if ($table == '') {
            if (! isset($this->from[0])) {
                throw new Kohana_Database_Exception('database.must_use_table');
            }

            $table = $this->from[0];
        }

        $sql = $this->driver->update($this->config['table_prefix'].$table, $this->set, $this->where);

        $this->reset_write();
        return $this->query($sql);
    }

    /**
     * Compiles a delete string and runs the query.
     *
     * @param   string  table name
     * @param   array   where clause
     * @return  Database_Result  Query result
     */
    public function delete($table = '', $where = null)
    {
        if ($table == '') {
            if (! isset($this->from[0])) {
                throw new Kohana_Database_Exception('database.must_use_table');
            }

            $table = $this->from[0];
        } else {
            $table = $this->config['table_prefix'].$table;
        }

        if (! is_null($where)) {
            $this->where($where);
        }

        if (count($this->where) < 1) {
            throw new Kohana_Database_Exception('database.must_use_where');
        }

        $sql = $this->driver->delete($table, $this->where);

        $this->reset_write();
        return $this->query($sql);
    }

    /**
     * Returns the last query run.
     *
     * @return  string SQL
     */
    public function last_query()
    {
        return $this->last_query;
    }

    /**
     * Count query records.
     *
     * @param   string   table name
     * @param   array    where clause
     * @return  integer
     */
    public function count_records($table = false, $where = null)
    {
        if (count($this->from) < 1) {
            if ($table == false) {

It seems like you are loosely comparing two booleans. Considering using the strict comparison === instead.

                throw new Kohana_Database_Exception('database.must_use_table');
            }

            $this->from($table);
        }

        if ($where !== null) {
            $this->where($where);
        }

        $query = $this->select('COUNT(*) AS '.$this->escape_column('records_found'))->get()->result(true);

        return (int) $query->current()->records_found;
    }

    /**
     * Resets all private select variables.
     *
     * @return  void
     */
    protected function reset_select()
    {
        $this->select   = array();
        $this->from     = array();
        $this->join     = array();
        $this->where    = array();
        $this->orderby  = array();
        $this->groupby  = array();
        $this->having   = array();
        $this->distinct = false;
        $this->limit    = false;
        $this->offset   = false;
    }

    /**
     * Resets all private insert and update variables.
     *
     * @return  void
     */
    protected function reset_write()
    {
        $this->set   = array();
        $this->from  = array();
        $this->where = array();
    }

    /**
     * Lists all the tables in the current database.
     *
     * @return  array
     */
    public function list_tables()
    {
        $this->link or $this->connect();

        return $this->driver->list_tables();
    }

    /**
     * See if a table exists in the database.
     *
     * @param   string   table name
     * @param   boolean  True to attach table prefix
     * @return  boolean
     */
    public function table_exists($table_name, $prefix = true)
    {
        if ($prefix) {
            return in_array($this->config['table_prefix'].$table_name, $this->list_tables());
        } else {
            return in_array($table_name, $this->list_tables());
        }
    }

    /**
     * Combine a SQL statement with the bind values. Used for safe queries.
     *
     * @param   string  query to bind to the values
     * @param   array   array of values to bind to the query
     * @param string $sql
     * @return  string
     */
    public function compile_binds($sql, $binds)
    {
        foreach ((array) $binds as $val) {
            // If the SQL contains no more bind marks ("?"), we're done.
            if (($next_bind_pos = strpos($sql, '?')) === false) {
                break;
            }

            // Properly escape the bind value.
            $val = $this->driver->escape($val);

            // Temporarily replace possible bind marks ("?"), in the bind value itself, with a placeholder.
            $val = str_replace('?', '{%B%}', $val);

            // Replace the first bind mark ("?") with its corresponding value.
            $sql = substr($sql, 0, $next_bind_pos).$val.substr($sql, $next_bind_pos + 1);
        }

        // Restore placeholders.
        return str_replace('{%B%}', '?', $sql);
    }

    /**
     * Get the field data for a database table, along with the field's attributes.
     *
     * @param   string  table name
     * @return  array
     */
    public function field_data($table = '')
    {
        $this->link or $this->connect();

        return $this->driver->field_data($this->config['table_prefix'].$table);
    }

    /**
     * Get the field data for a database table, along with the field's attributes.
     *
     * @param   string  table name
     * @return  array
     */
    public function list_fields($table = '')
    {
        $this->link or $this->connect();

        return $this->driver->list_fields($this->config['table_prefix'].$table);
    }

    /**
     * Escapes a value for a query.
     *
     * @param   mixed   value to escape
     * @return  string
     */
    public function escape($value)
    {
        return $this->driver->escape($value);
    }

    /**
     * Escapes a string for a query.
     *
     * @param   string  string to escape
     * @return  string
     */
    public function escape_str($str)
    {
        return $this->driver->escape_str($str);
    }

    /**
     * Escapes a table name for a query.
     *
     * @param   string  string to escape
     * @param string $table
     * @return  string
     */
    public function escape_table($table)
    {
        return $this->driver->escape_table($table);
    }

    /**
     * Escapes a column name for a query.
     *
     * @param   string  string to escape
     * @param string $table
     * @return  string
     */
    public function escape_column($table)
    {
        return $this->driver->escape_column($table);
    }

    /**
     * Returns table prefix of current configuration.
     *
     * @return  string
     */
    public function table_prefix()
    {
        return $this->config['table_prefix'];
    }

    /**
     * Clears the query cache.
     *
     * @param   string|TRUE  clear cache by SQL statement or TRUE for last query
     * @return  Database_Core       This Database object.
     */
    public function clear_cache($sql = null)
    {
        if ($sql === true) {
            $this->driver->clear_cache($this->last_query);
        } elseif (is_string($sql)) {
            $this->driver->clear_cache($sql);
        } else {
            $this->driver->clear_cache();
        }

        return $this;
    }

    /**
     * Pushes existing query space onto the query stack.  Use push
     * and pop to prevent queries from clashing before they are
     * executed
     *
     * @return Database_Core This Databaes object
     */
    public function push()
    {
        array_push($this->query_history, array(
            $this->select,
            $this->from,
            $this->join,
            $this->where,
            $this->orderby,
            $this->order,
            $this->groupby,
            $this->having,
            $this->distinct,
            $this->limit,
            $this->offset
        ));

        $this->reset_select();

        return $this;
    }

    /**
     * Pops from query stack into the current query space.
     *
     * @return Database_Core This Databaes object
     */
    public function pop()
    {
        if (count($this->query_history) == 0) {
            // No history
            return $this;
        }

        list(
            $this->select,
            $this->from,
            $this->join,
            $this->where,
            $this->orderby,
            $this->order,
            $this->groupby,
            $this->having,
            $this->distinct,
            $this->limit,
            $this->offset
        ) = array_pop($this->query_history);

        return $this;
    }

    /**
     * Count the number of records in the last query, without LIMIT or OFFSET applied.
     *
     * @return  integer

Should the return type not be integer|false?

     */
    public function count_last_query()
    {
        if ($sql = $this->last_query()) {
            if (stripos($sql, 'LIMIT') !== false) {
                // Remove LIMIT from the SQL
                $sql = preg_replace('/\sLIMIT\s+[^a-z]+/i', ' ', $sql);
            }

            if (stripos($sql, 'OFFSET') !== false) {
                // Remove OFFSET from the SQL
                $sql = preg_replace('/\sOFFSET\s+\d+/i', '', $sql);
            }

            // Get the total rows from the last query executed
            $result = $this->query(
                'SELECT COUNT(*) AS '.$this->escape_column('total_rows').' '.
                'FROM ('.trim($sql).') AS '.$this->escape_table('counted_results')
            );

            // Return the total number of rows from the query
            return (int) $result->current()->total_rows;
        }

        return false;
    }
} // End Database Class


/**
 * Sets the code for a Database exception.
 */
class Kohana_Database_Exception extends Kohana_Exception
{
    protected $code = E_DATABASE_ERROR;
} // End Kohana Database Exception