qubaid_join Class Reference

Inheritance diagram for qubaid_join:

Collaboration diagram for qubaid_join:

Public Member Functions
	__construct ($from, $usageidcolumn, $where= '', $params=array())
	from_question_attempts ($alias)
	where ()
	from_where_params ()
	usage_id_in ()
	usage_id_in_params ()
Data Fields
	$from
	$usageidcolumn
	$where
	$params

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Detailed Description

This class represents a restriction on the set of question_usage ids to include in a larger database query based on JOINing to some other tables.

The general form of the query is something like

SELECT qa.id, qa.maxmark FROM $from JOIN {question_attempts} qa ON qa.questionusageid = $usageidcolumn WHERE $where AND qa.slot = 1

where $from, $usageidcolumn and $where are the arguments to the constructor.

Copyright:

2010 The Open University http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

Definition at line 1434 of file datalib.php.

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Constructor & Destructor Documentation

__construct	(	$	from,
		$	usageidcolumn,
		$	where = '',
		$	params = array()
	)

Constructor. The meaning of the arguments is explained in the class comment.

Parameters:

string	$from	SQL fragemnt to go in the FROM clause.
string	$usageidcolumn	the column in $from that should be made equal to the usageid column in the JOIN clause.
string	$where	SQL fragment to go in the where clause.
array	$params	required by the SQL. You must use named parameters.

Definition at line 1448 of file datalib.php.

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Member Function Documentation

from_question_attempts

(

$

alias

)

Returns:

string the SQL that needs to go in the FROM clause when trying to select records from the 'question_attempts' table based on the qubaid_condition.

Reimplemented from qubaid_condition.

Definition at line 1458 of file datalib.php.

from_where_params

(

)

Returns:

the params needed by a query that uses from_question_attempts() and where().

Reimplemented from qubaid_condition.

Definition at line 1468 of file datalib.php.

usage_id_in

(

)

Returns:

string SQL that can use used in a WHERE qubaid IN (...) query. This method returns the "IN (...)" part.

Reimplemented from qubaid_condition.

Definition at line 1472 of file datalib.php.

usage_id_in_params

(

)

Returns:

the params needed by a query that uses usage_id_in().

Reimplemented from qubaid_condition.

Definition at line 1476 of file datalib.php.

where

(

)

Returns:

string the SQL that needs to go in the where clause.

Reimplemented from qubaid_condition.

Definition at line 1464 of file datalib.php.

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Field Documentation

$from

Definition at line 1435 of file datalib.php.

$params

Definition at line 1438 of file datalib.php.

$usageidcolumn

Definition at line 1436 of file datalib.php.

$where

Definition at line 1437 of file datalib.php.

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The documentation for this class was generated from the following file:

• C:/xampp/htdocs/moodle/question/engine/datalib.php