1 views_plugin_query_default.inc | views_plugin_query_default::add_relationship($alias, $join, $base, $link_point = NULL) |
A relationship is an alternative endpoint to a series of table joins. Relationships must be aliases of the primary table and they must join either to the primary table or to a pre-existing relationship.
An example of a relationship would be an entity reference table. If you have a entity reference named 'book_parent' which links to a parent node, you could set up a relationship 'node_book_parent' to 'node'. Then, anything that links to 'node' can link to 'node_book_parent' instead, thus allowing all properties of both nodes to be available in the query.
Parameters
$alias: What this relationship will be called, and is also the alias for the table.
views_join $join: A views_join object (or derived object) to join the alias in.
$base: The name of the 'base' table this relationship represents; this tells the join search which path to attempt to use when finding the path to this relationship.
$link_point: If this relationship links to something other than the primary table, specify that table here. For example, a 'track' node might have a relationship to an 'album' node, which might have a relationship to an 'artist' node.
File
- core/
modules/ views/ plugins/ views_plugin_query_default.inc, line 323 - Defines the default query object.
Class
- views_plugin_query_default
- Object used to create a SELECT query.
Code
function add_relationship($alias, $join, $base, $link_point = NULL) {
if (empty($link_point)) {
$link_point = $this->base_table;
}
elseif (!array_key_exists($link_point, $this->relationships)) {
return FALSE;
}
// Make sure $alias isn't already used; if it, start adding stuff.
$alias_base = $alias;
$count = 1;
while (!empty($this->relationships[$alias])) {
$alias = $alias_base . '_' . $count++;
}
// Make sure this join is adjusted for our relationship.
if ($link_point && isset($this->relationships[$link_point])) {
$join = $this->adjust_join($join, $link_point);
}
// Add the table directly to the queue to avoid accidentally marking
// it.
$this->table_queue[$alias] = array(
'table' => $join->table,
'num' => 1,
'alias' => $alias,
'join' => $join,
'relationship' => $link_point,
);
$this->relationships[$alias] = array(
'link' => $link_point,
'table' => $join->table,
'base' => $base,
);
$this->tables[$this->base_table][$alias] = array(
'count' => 1,
'alias' => $alias,
);
return $alias;
}