File Source for Join.class.php

<?php
/**
* @package databases
*/
/**
* @package databases
* @version 0.1.31
* @author Daniel PlÃ¼cken <daniel@debakel.net>
* @license http://www.gnu.org/copyleft/lesser.html
* GNU Lesser General Public License
* @copyright Copyright (C) 2004 Daniel PlÃ¼cken <daniel@debakel.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*/
class Join
{
/**
* The left databasetable's object of this join.
*
* @var object $dbt_left
* @access public
*/
var $dbt_left = null;
/**
* The right databasetable's object of this join.
*
* @var object $dbt_right
* @access public
*/
var $dbt_right = null;
/**
* Carries the left fieldnames of this join.
* Note that fieldnames in a join could also be values. It isn't necessary to
* join one fieldname to another.
*
* @var array $left_field
* @access private
*/
var $left_field = "";
/**
* Carries the right fieldnames of this join.
* Note that fieldnames in a join could also be values. It isn't necessary to
* join one fieldname to another.
*
* @var array $right_field
* @access private
*/
var $right_field = "";
/**
* Carries an alias of the tablename of $this->dbt_left.
*
* @var array $alias_left
* @access private
*/
var $alias_left = "";
/**
* Carries an alias of the tablename of $this->dbt_right.
*
* @var array $alias_right
* @access public
*/
var $alias_right = "";
/**
* Carries the relational operators between the fields in the "ON"-Clause of
* the join.
*
* @var array $join_operator
* @access public
*/
var $relational_operator = array();
/**
* Carries the logical operators between the relational statements in the
* "ON"-Clause of the join.
*
* @var array $join_operator
* @access public
*/
var $logical_operator = array();
/**
* Carries the type of join. Can be INNER, CROSS, LEFT [OUTER], RIGHT [OUTER]
* or NATURAL [LEFT | RIGTH [OUTER]]. The Standard is LEFT, because it was the
* only used join in the past.
*
* @var string $type
* @access public
*/
var $type = "LEFT";
/**
* Constructor
*
* @version 1.2
* @since 0.1.0
* @author Daniel PlÃ¼cken <daniel@debakel.net>
* @access public
* @param object $dbt_left
* @param object $dbt_right
* @param mixed $left_field A fieldname of $dbt_left which should get
* a join or a condition for $right_field.
* @param mixed $right_field A fieldname that should join to $left_field.
* @param string $alias_left* An alias for the tablename of $dbt_left.
* @param string $alias_right* An alias for the tablename of $dbt_right.
* @return Join
*/
function Join(
&$dbt_left, &$dbt_right,
$left_field, $right_field,
$alias_left = "l", $alias_right = "r",
$logical_operator = array(),
$relational_operator = array()
)
{
if(
is_a( $dbt_left, "ABSTDatabaseTable" )
|| is_subclass_of( $dbt_left, "ABSTDatabaseTable" )
)
$this->dbt_left = &$dbt_left;
else
die(
"<h3>The parameter dbt_left does not "
."refer to a valid database's object!</h3>"
);
if(
is_a( $dbt_right, "ABSTDatabaseTable" )
|| is_subclass_of( $dbt_right, "ABSTDatabaseTable" )
)
$this->dbt_right = &$dbt_right;
else
die(
"<h3>The parameter dbt_right does not "
."refer to a valid database's object!</h3>"
);
if( is_array( $left_field ) )
$this->left_field = $left_field;
else
$this->left_field[] = $left_field;
if( is_array( $right_field ) )
$this->right_field = $right_field;
else
$this->right_field[] = $right_field;
if( is_array( $logical_operator ) )
$this->logical_operator = $logical_operator;
else
$this->logical_operator[] = $logical_operator;
if( is_array( $relational_operator ) )
$this->relational_operator = $relational_operator;
else
$this->relational_operator[] = $relational_operator;
$this->alias_left = $alias_left;
$this->alias_right = $alias_right;
}
/**
* Sets the type of join. Has to be INNER, CROSS, LEFT [OUTER], RIGHT [OUTER]
* or NATURAL [LEFT | RIGTH [OUTER]]
*
* @version 1.01
* @since 0.1.3
* @author Daniel PlÃ¼cken <daniel@debakel.net>
* @access public
* @param string $left_field A fieldname of $dbt_left which should get a
* join or a condition for $right_field.
* @param string $right_field A fieldname that should join to $left_field.
* @return void
*/
function setType( $string )
{
if (
$string == ""
|| preg_match(
"!^(?:"
."(?:LEFT|RIGHT)(?:\s+OUTER)?"
."|INNER|CROSS"
."|NATURAL(?:\s+(?:LEFT|RIGHT)(?:\s+OUTER)?)?"
.")$!i", $string
)
)
{ $this->type = strtoupper( $string ); }
}
/**
* Adds Fields to this join.
*
* @version 1.0
* @since 0.1.1
* @author Daniel PlÃ¼cken ( daniel@debakel.net )
* @access public
* @param string $left_field A fieldname of $dbt_left which should get a
* join or a condition for $right_field.
* @param string $right_field A fieldname that should join to $left_field.
* @return void
*/
function addFields()
{
$param = func_get_args();
if( count( $param ) % 2 == 1 )
array_pop( $param );
for( $i = 0; $i < count( $param ); $i++)
{
if(
$i % 2 == 0
&& !empty( $param[$i] )
)
$this->left_field[] = $param[$i];
if(
$i % 2 == 1
&& !empty( $param[$i] )
)
$this->right_field[] = $param[$i];
}
}
/**
* Swaps the left-right definition. The reference from the left table moves
* to the reference of the right database table and the other way around.
* This is useful for some complications with the join generation.
*
* @version 1.0
* @since 0.1.2
* @author Daniel PlÃ¼cken <daniel@debakel.net>
* @access public
* @return void
*/
function swapLeftRight()
{
$help_ref = &$this->alias_left;
unset( $this->alias_left );
$this->alias_left =& $this->alias_right;
unset( $this->alias_right );
$this->alias_right =& $help_ref;
unset( $help_ref );
$help_ref = &$this->left_field;
unset( $this->left_field );
$this->left_field =& $this->right_field;
unset( $this->right_field );
$this->right_field =& $help_ref;
unset( $help_ref );
$help_ref = &$this->dbt_left;
unset( $this->dbt_left );
$this->dbt_left =& $this->dbt_right;
unset( $this->dbt_right );
$this->dbt_right =& $help_ref;
unset( $help_ref );
}
} // End of class Join
?>

Source for file Join.class.php