core\dml\sql_join Class Reference

An object that contains sql join fragments. More...

Public Member Functions
	__construct ($joins='', $wheres='', $params=array(), $cannotmatchanyrows=false)
	Create an object that contains sql join fragments.

Public Attributes
bool	$cannotmatchanyrows
	if true this join is guaranteed to never match any rows.
string	$joins
	joins.
array	$params
	params.
string	$wheres
	wheres.

Detailed Description

An object that contains sql join fragments.

An example of how to use this class in a simple query, where you have got a join that is a join to the user table:

$users = $DB->get_records_sql("SELECT u.* FROM {user} u {$sqljoin->joins} WHERE {$sqljoin->wheres}", $sqljoin->params);

Since

Moodle 3.1

Copyright

2016 The Open University

License

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

Constructor & Destructor Documentation

__construct()

core\dml\sql_join::__construct	(		$joins = '',
			$wheres = '',
			$params = array(),
			$cannotmatchanyrows = false )

Create an object that contains sql join fragments.

Note, even if you set $cannotmatchanyrows to true, it is important to also set the other fields because the calling code is not required to check it. For example new core\dml\sql_join('', '1 = 2', [], true);

Parameters

string	$joins	The join sql fragment.
string	$wheres	The where sql fragment.
array	$params	Any parameter values.
bool	$cannotmatchanyrows	If true, this join is guaranteed to match no rows. See comment on the field above.

Member Data Documentation

$cannotmatchanyrows

bool core\dml\sql_join::$cannotmatchanyrows

if true this join is guaranteed to never match any rows.

In this case, the calling code may be able to completely skip doing the database query.

Since

Moodle 3.9/3.8.3/3.7.6.

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

• lib/classes/dml/sql_join.php