qubaid_condition Class Reference

This class represents a restriction on the set of question_usage ids to include in a larger database query. More...

Inheritance diagram for qubaid_condition:

Public Member Functions
	from_question_attempts ($alias)
	Get the SQL fragment to go in a FROM clause. More...
	from_where_params ()
	get_hash_code ()
	usage_id_in ()
	usage_id_in_params ()
	where ()

Detailed Description

This class represents a restriction on the set of question_usage ids to include in a larger database query.

Depending of the how you are going to restrict the list of usages, construct an appropriate subclass.

If $qubaids is an instance of this class, example usage might be

SELECT qa.id, qa.maxmark FROM $qubaids->from_question_attempts('qa') WHERE $qubaids->where() AND qa.slot = 1

Copyright

2010 The Open University

License

http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

Member Function Documentation

from_question_attempts()

qubaid_condition::from_question_attempts (   $alias )

abstract

Get the SQL fragment to go in a FROM clause.

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

Parameters

string

$alias

Return values

string

SQL fragment.

Reimplemented in qubaid_list, and qubaid_join.

from_where_params()

qubaid_condition::from_where_params ( )

abstract

Return values

array

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

Reimplemented in qubaid_list, and qubaid_join.

get_hash_code()

qubaid_condition::get_hash_code

(

)

Return values

string

40-character hash code that uniquely identifies the combination of properties and class name of this qubaid condition.

usage_id_in()

qubaid_condition::usage_id_in ( )

abstract

Return values

string

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

Reimplemented in qubaid_list, and qubaid_join.

usage_id_in_params()

qubaid_condition::usage_id_in_params ( )

abstract

Return values

array

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

Reimplemented in qubaid_list, and qubaid_join.

where()

qubaid_condition::where ( )

abstract

Return values

string

the SQL that needs to go in the where clause.

Reimplemented in qubaid_list, and qubaid_join.

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

• question/engine/datalib.php