Class Kohana_Database

Kohana_Database

Database connection wrapper/helper.

You may get a database instance using Database::instance('name') where name is the config group.

This class provides connection instance management via Database Drivers, as well as quoting, escaping and other related functions. Querys are done using Database_Query and Database_Query_Builder objects, which can be easily created using the DB helper class.

package
Kohana/Database
category
Base
author
Kohana Team
copyright
(c) Kohana Team
license
https://koseven.ga/LICENSE.md


Constants

SELECT

integer 1

INSERT

integer 2

UPDATE

integer 3

DELETE

integer 4

Properties

public static string $default

default instance name

string(7) "default"

public static array $instances

Database instances

array(0) 

public string $last_query

the last query executed

Default value:
NULL

protected $_config

Default value:
NULL

protected $_connection

Default value:
NULL

protected $_identifier

Default value:
string(1) """

protected $_instance

Default value:
NULL

Methods

public __construct() (defined in Kohana_Database)

Stores the database configuration locally and name the instance.

This method cannot be accessed directly, you must use Database::instance.

Return Values

  • void

Source Code

public function __construct($name, array $config)
{
	// Set the instance name
	$this->_instance = $name;

	// Store the config locally
	$this->_config = $config;

	if (empty($this->_config['table_prefix']))
	{
		$this->_config['table_prefix'] = '';
	}
}

public __destruct() (defined in Kohana_Database)

Disconnect from the database when the object is destroyed.

// Destroy the database instance
unset(Database::instances[(string) $db], $db);

Calling unset($db) is not enough to destroy the database, as it will still be stored in Database::$instances.

Return Values

  • void

Source Code

public function __destruct()
{
	$this->disconnect();
}

public __toString() (defined in Kohana_Database)

Returns the database instance name.

echo (string) $db;

Return Values

  • string

Source Code

public function __toString()
{
	return $this->_instance;
}

abstract public begin([ string $mode = NULL ] ) (defined in Kohana_Database)

Start a SQL transaction

// Start the transactions
$db->begin();

try {
     DB::insert('users')->values($user1)...
     DB::insert('users')->values($user2)...
     // Insert successful commit the changes
     $db->commit();
}
catch (Database_Exception $e)
{
     // Insert failed. Rolling back changes...
     $db->rollback();
 }

Parameters

  • string $mode = NULL - Transaction mode

Return Values

  • boolean

Source Code

abstract public function begin($mode = NULL);

abstract public commit() (defined in Kohana_Database)

Commit the current transaction

// Commit the database changes
$db->commit();

Return Values

  • boolean

Source Code

abstract public function commit();

abstract public connect() (defined in Kohana_Database)

Connect to the database. This is called automatically when the first query is executed.

$db->connect();

Tags

Return Values

  • void

Source Code

abstract public function connect();

public count_records(mixed $table ) (defined in Kohana_Database)

Count the number of records in a table.

// Get the total number of records in the "users" table
$count = $db->count_records('users');

Parameters

  • mixed $table required - Table name string or array(query, alias)

Return Values

  • integer

Source Code

public function count_records($table)
{
	// Quote the table name
	$table = $this->quote_table($table);

	return $this->query(Database::SELECT, 'SELECT COUNT(*) AS total_row_count FROM '.$table, FALSE)
		->get('total_row_count');
}

public datatype(string $type ) (defined in Kohana_Database)

Returns a normalized array describing the SQL data type

$db->datatype('char');

Parameters

  • string $type required - SQL data type

Return Values

  • array

Source Code

public function datatype($type)
{
	static $types = [
		// SQL-92
		'bit'                           => ['type' => 'string', 'exact' => TRUE],
		'bit varying'                   => ['type' => 'string'],
		'char'                          => ['type' => 'string', 'exact' => TRUE],
		'char varying'                  => ['type' => 'string'],
		'character'                     => ['type' => 'string', 'exact' => TRUE],
		'character varying'             => ['type' => 'string'],
		'date'                          => ['type' => 'string'],
		'dec'                           => ['type' => 'float', 'exact' => TRUE],
		'decimal'                       => ['type' => 'float', 'exact' => TRUE],
		'double precision'              => ['type' => 'float'],
		'float'                         => ['type' => 'float'],
		'int'                           => ['type' => 'int', 'min' => '-2147483648', 'max' => '2147483647'],
		'integer'                       => ['type' => 'int', 'min' => '-2147483648', 'max' => '2147483647'],
		'interval'                      => ['type' => 'string'],
		'national char'                 => ['type' => 'string', 'exact' => TRUE],
		'national char varying'         => ['type' => 'string'],
		'national character'            => ['type' => 'string', 'exact' => TRUE],
		'national character varying'    => ['type' => 'string'],
		'nchar'                         => ['type' => 'string', 'exact' => TRUE],
		'nchar varying'                 => ['type' => 'string'],
		'numeric'                       => ['type' => 'float', 'exact' => TRUE],
		'real'                          => ['type' => 'float'],
		'smallint'                      => ['type' => 'int', 'min' => '-32768', 'max' => '32767'],
		'time'                          => ['type' => 'string'],
		'time with time zone'           => ['type' => 'string'],
		'timestamp'                     => ['type' => 'string'],
		'timestamp with time zone'      => ['type' => 'string'],
		'varchar'                       => ['type' => 'string'],

		// SQL:1999
		'binary large object'               => ['type' => 'string', 'binary' => TRUE],
		'blob'                              => ['type' => 'string', 'binary' => TRUE],
		'boolean'                           => ['type' => 'bool'],
		'char large object'                 => ['type' => 'string'],
		'character large object'            => ['type' => 'string'],
		'clob'                              => ['type' => 'string'],
		'national character large object'   => ['type' => 'string'],
		'nchar large object'                => ['type' => 'string'],
		'nclob'                             => ['type' => 'string'],
		'time without time zone'            => ['type' => 'string'],
		'timestamp without time zone'       => ['type' => 'string'],

		// SQL:2003
		'bigint'    => ['type' => 'int', 'min' => '-9223372036854775808', 'max' => '9223372036854775807'],

		// SQL:2008
		'binary'            => ['type' => 'string', 'binary' => TRUE, 'exact' => TRUE],
		'binary varying'    => ['type' => 'string', 'binary' => TRUE],
		'varbinary'         => ['type' => 'string', 'binary' => TRUE],
	];

	if (isset($types[$type]))
		return $types[$type];

	return [];
}

public disconnect() (defined in Kohana_Database)

Disconnect from the database. This is called automatically by Database::__destruct. Clears the database instance from Database::$instances.

$db->disconnect();

Return Values

  • boolean

Source Code

public function disconnect()
{
	unset(Database::$instances[$this->_instance]);

	return TRUE;
}

abstract public escape(string $value ) (defined in Kohana_Database)

Sanitize a string by escaping characters that could cause an SQL injection attack.

$value = $db->escape('any string');

Parameters

  • string $value required - Value to quote

Return Values

  • string

Source Code

abstract public function escape($value);

public static instance([ string $name = NULL , array $config = NULL ] ) (defined in Kohana_Database)

Get a singleton Database instance. If configuration is not specified, it will be loaded from the database configuration file using the same group as the name.

// Load the default database
$db = Database::instance();

// Create a custom configured instance
$db = Database::instance('custom', $config);

Parameters

  • string $name = NULL - Instance name
  • array $config = NULL - Configuration parameters

Return Values

  • Database

Source Code

public static function instance($name = NULL, array $config = NULL)
{
	if ($name === NULL)
	{
		// Use the default instance name
		$name = Database::$default;
	}

	if ( ! isset(Database::$instances[$name]))
	{
		if ($config === NULL)
		{
			// Load the configuration for this database
			$config = Kohana::$config->load('database')->$name;
		}

		if ( ! isset($config['type']))
		{
			throw new Kohana_Exception('Database type not defined in :name configuration',
				[':name' => $name]);
		}

		// Set the driver class name
		$driver = 'Database_'.ucfirst($config['type']);

		// Create the database connection instance
		$driver = new $driver($name, $config);

		// Store the database instance
		Database::$instances[$name] = $driver;
	}

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

abstract public list_columns(string $table [, string $like = NULL , boolean $add_prefix = bool TRUE ] ) (defined in Kohana_Database)

Lists all of the columns in a table. Optionally, a LIKE string can be used to search for specific fields.

// Get all columns from the "users" table
$columns = $db->list_columns('users');

// Get all name-related columns
$columns = $db->list_columns('users', '%name%');

// Get the columns from a table that doesn't use the table prefix
$columns = $db->list_columns('users', NULL, FALSE);

Parameters

  • string $table required - Table to get columns from
  • string $like = NULL - Column to search for
  • boolean $add_prefix = bool TRUE - Whether to add the table prefix automatically or not

Return Values

  • array

Source Code

abstract public function list_columns($table, $like = NULL, $add_prefix = TRUE);

abstract public list_tables([ string $like = NULL ] ) (defined in Kohana_Database)

List all of the tables in the database. Optionally, a LIKE string can be used to search for specific tables.

// Get all tables in the current database
$tables = $db->list_tables();

// Get all user-related tables
$tables = $db->list_tables('user%');

Parameters

  • string $like = NULL - Table to search for

Return Values

  • array

Source Code

abstract public function list_tables($like = NULL);

abstract public query(integer $type , string $sql [, mixed $as_object = bool FALSE , array $params = NULL ] ) (defined in Kohana_Database)

Perform an SQL query of the given type.

// Make a SELECT query and use objects for results
$db->query(Database::SELECT, 'SELECT * FROM groups', TRUE);

// Make a SELECT query and use "Model_User" for the results
$db->query(Database::SELECT, 'SELECT * FROM users LIMIT 1', 'Model_User');

Parameters

  • integer $type required - Database::SELECT, Database::INSERT, etc
  • string $sql required - SQL query
  • mixed $as_object = bool FALSE - Result object class string, TRUE for stdClass, FALSE for assoc array
  • array $params = NULL - Object construct parameters for result class

Return Values

  • object - Database_Result for SELECT queries
  • array - List (insert id, row count) for INSERT queries
  • integer - Number of affected rows for all other queries

Source Code

abstract public function query($type, $sql, $as_object = FALSE, array $params = NULL);

public quote(mixed $value ) (defined in Kohana_Database)

Quote a value for an SQL query.

$db->quote(NULL);   // 'NULL'
$db->quote(10);     // 10
$db->quote('fred'); // 'fred'

Objects passed to this function will be converted to strings. Database_Expression objects will be compiled. Database_Query objects will be compiled and converted to a sub-query. All other objects will be converted using the __toString method.

Parameters

  • mixed $value required - Any value to quote

Tags

Return Values

  • string

Source Code

public function quote($value)
{
	if ($value === NULL)
	{
		return 'NULL';
	}
	elseif ($value === TRUE)
	{
		return "'1'";
	}
	elseif ($value === FALSE)
	{
		return "'0'";
	}
	elseif (is_object($value))
	{
		if ($value instanceof Database_Query)
		{
			// Create a sub-query
			return '('.$value->compile($this).')';
		}
		elseif ($value instanceof Database_Expression)
		{
			// Compile the expression
			return $value->compile($this);
		}
		else
		{
			// Convert the object to a string
			return $this->quote( (string) $value);
		}
	}
	elseif (is_array($value))
	{
		return '('.implode(', ', array_map([$this, __FUNCTION__], $value)).')';
	}
	elseif (is_int($value))
	{
		return (int) $value;
	}
	elseif (is_float($value))
	{
		// Convert to non-locale aware float to prevent possible commas
		return sprintf('%F', $value);
	}

	return $this->escape($value);
}

public quote_column(mixed $column ) (defined in Kohana_Database)

Quote a database column name and add the table prefix if needed.

$column = $db->quote_column($column);

You can also use SQL methods within identifiers.

$column = $db->quote_column(DB::expr('COUNT(`column`)'));

Objects passed to this function will be converted to strings. Database_Expression objects will be compiled. Database_Query objects will be compiled and converted to a sub-query. All other objects will be converted using the __toString method.

Parameters

  • mixed $column required - Column name or array(column, alias)

Tags

Return Values

  • string

Source Code

public function quote_column($column)
{
	// Identifiers are escaped by repeating them
	$escaped_identifier = $this->_identifier.$this->_identifier;

	if (is_array($column))
	{
		list($column, $alias) = $column;
		$alias = str_replace($this->_identifier, $escaped_identifier, $alias);
	}

	if ($column instanceof Database_Query)
	{
		// Create a sub-query
		$column = '('.$column->compile($this).')';
	}
	elseif ($column instanceof Database_Expression)
	{
		// Compile the expression
		$column = $column->compile($this);
	}
	else
	{
		// Convert to a string
		$column = (string) $column;

		$column = str_replace($this->_identifier, $escaped_identifier, $column);

		if ($column === '*')
		{
			return $column;
		}
		elseif (strpos($column, '.') !== FALSE)
		{
			$parts = explode('.', $column);

			if ($prefix = $this->table_prefix())
			{
				// Get the offset of the table name, 2nd-to-last part
				$offset = count($parts) - 2;

				// Add the table prefix to the table name
				$parts[$offset] = $prefix.$parts[$offset];
			}

			foreach ($parts as & $part)
			{
				if ($part !== '*')
				{
					// Quote each of the parts
					$part = $this->_identifier.$part.$this->_identifier;
				}
			}

			$column = implode('.', $parts);
		}
		else
		{
			$column = $this->_identifier.$column.$this->_identifier;
		}
	}

	if (isset($alias))
	{
		$column .= ' AS '.$this->_identifier.$alias.$this->_identifier;
	}

	return $column;
}

public quote_identifier(mixed $value ) (defined in Kohana_Database)

Quote a database identifier

Objects passed to this function will be converted to strings. Database_Expression objects will be compiled. Database_Query objects will be compiled and converted to a sub-query. All other objects will be converted using the __toString method.

Parameters

  • mixed $value required - Any identifier

Return Values

  • string

Source Code

public function quote_identifier($value)
{
	// Identifiers are escaped by repeating them
	$escaped_identifier = $this->_identifier.$this->_identifier;

	if (is_array($value))
	{
		list($value, $alias) = $value;
		$alias = str_replace($this->_identifier, $escaped_identifier, $alias);
	}

	if ($value instanceof Database_Query)
	{
		// Create a sub-query
		$value = '('.$value->compile($this).')';
	}
	elseif ($value instanceof Database_Expression)
	{
		// Compile the expression
		$value = $value->compile($this);
	}
	else
	{
		// Convert to a string
		$value = (string) $value;

		$value = str_replace($this->_identifier, $escaped_identifier, $value);

		if (strpos($value, '.') !== FALSE)
		{
			$parts = explode('.', $value);

			foreach ($parts as & $part)
			{
				// Quote each of the parts
				$part = $this->_identifier.$part.$this->_identifier;
			}

			$value = implode('.', $parts);
		}
		else
		{
			$value = $this->_identifier.$value.$this->_identifier;
		}
	}

	if (isset($alias))
	{
		$value .= ' AS '.$this->_identifier.$alias.$this->_identifier;
	}

	return $value;
}

public quote_table(mixed $table ) (defined in Kohana_Database)

Quote a database table name and adds the table prefix if needed.

$table = $db->quote_table($table);

Objects passed to this function will be converted to strings. Database_Expression objects will be compiled. Database_Query objects will be compiled and converted to a sub-query. All other objects will be converted using the __toString method.

Parameters

  • mixed $table required - Table name or array(table, alias)

Tags

Return Values

  • string

Source Code

public function quote_table($table)
{
	// Identifiers are escaped by repeating them
	$escaped_identifier = $this->_identifier.$this->_identifier;

	if (is_array($table))
	{
		list($table, $alias) = $table;
		$alias = str_replace($this->_identifier, $escaped_identifier, $alias);
	}

	if ($table instanceof Database_Query)
	{
		// Create a sub-query
		$table = '('.$table->compile($this).')';
	}
	elseif ($table instanceof Database_Expression)
	{
		// Compile the expression
		$table = $table->compile($this);
	}
	else
	{
		// Convert to a string
		$table = (string) $table;

		$table = str_replace($this->_identifier, $escaped_identifier, $table);

		if (strpos($table, '.') !== FALSE)
		{
			$parts = explode('.', $table);

			if ($prefix = $this->table_prefix())
			{
				// Get the offset of the table name, last part
				$offset = count($parts) - 1;

				// Add the table prefix to the table name
				$parts[$offset] = $prefix.$parts[$offset];
			}

			foreach ($parts as & $part)
			{
				// Quote each of the parts
				$part = $this->_identifier.$part.$this->_identifier;
			}

			$table = implode('.', $parts);
		}
		else
		{
			// Add the table prefix
			$table = $this->_identifier.$this->table_prefix().$table.$this->_identifier;
		}
	}

	if (isset($alias))
	{
		// Attach table prefix to alias
		$table .= ' AS '.$this->_identifier.$this->table_prefix().$alias.$this->_identifier;
	}

	return $table;
}

abstract public rollback() (defined in Kohana_Database)

Abort the current transaction

// Undo the changes
$db->rollback();

Return Values

  • boolean

Source Code

abstract public function rollback();

abstract public set_charset(string $charset ) (defined in Kohana_Database)

Set the connection character set. This is called automatically by Database::connect.

$db->set_charset('utf8');

Parameters

  • string $charset required - Character set name

Tags

Return Values

  • void

Source Code

abstract public function set_charset($charset);

public table_prefix() (defined in Kohana_Database)

Return the table prefix defined in the current configuration.

$prefix = $db->table_prefix();

Return Values

  • string

Source Code

public function table_prefix()
{
	return $this->_config['table_prefix'];
}

protected _parse_type(string $type ) (defined in Kohana_Database)

Extracts the text between parentheses, if any.

// Returns: array('CHAR', '6')
list($type, $length) = $db->_parse_type('CHAR(6)');

Parameters

  • string $type required - $type

Return Values

  • array - List containing the type and length, if any

Source Code

protected function _parse_type($type)
{
	if (($open = strpos($type, '(')) === FALSE)
	{
		// No length specified
		return [$type, NULL];
	}

	// Closing parenthesis
	$close = strrpos($type, ')', $open);

	// Length without parentheses
	$length = substr($type, $open + 1, $close - 1 - $open);

	// Type without the length
	$type = substr($type, 0, $open).substr($type, $close + 1);

	return [$type, $length];
}

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