setJoinClass($joinClass); $this->setLocalKey($localKey); $this->setForeignKey($foreignKey); } /** * @return string */ public function getJoinClass() { return $this->joinClass; } /** * @param mixed $joinClass * @return $this */ public function setJoinClass($joinClass) { $this->joinClass = $joinClass; return $this; } /** * @return string */ public function getLocalKey() { return $this->localKey; } /** * @param string $localKey * @return $this */ public function setLocalKey($localKey) { $this->localKey = $localKey; return $this; } /** * @return string */ public function getForeignKey() { return $this->foreignKey; } /** * @param string $foreignKey * @return $this */ public function setForeignKey($foreignKey) { $this->foreignKey = $foreignKey; return $this; } /** * Get has_many relationship between parent and join table (for a given DataQuery) * * @param DataQuery $query * @return HasManyList */ public function getParentRelationship(DataQuery $query) { // Create has_many $list = HasManyList::create($this->getJoinClass(), $this->getForeignKey()); $list = $list->setDataQueryParam($this->extractInheritableQueryParameters($query)); // Limit to given foreign key if ($foreignID = $query->getQueryParam('Foreign.ID')) { $list = $list->forForeignID($foreignID); } return $list; } /** * Calculate the query parameters that should be inherited from the base many_many * to the nested has_many list. * * @param DataQuery $query * @return mixed */ public function extractInheritableQueryParameters(DataQuery $query) { $params = $query->getQueryParams(); // Remove `Foreign.` query parameters for created objects, // as this would interfere with relations on those objects. foreach(array_keys($params) as $key) { if(stripos($key, 'Foreign.') === 0) { unset($params[$key]); } } // Get inheritable parameters from an instance of the base query dataclass $inst = Injector::inst()->create($query->dataClass()); $inst->setSourceQueryParams($params); return $inst->getInheritableQueryParams(); } /** * Get name of join table alias for use in queries. * * @return string */ public function getJoinAlias() { return DataObject::getSchema()->tableName($this->getJoinClass()); } /** * Invoked prior to getFinalisedQuery() * * @param DataQuery $dataQuery * @param array $queriedColumns * @param SQLSelect $sqlSelect */ public function beforeGetFinalisedQuery(DataQuery $dataQuery, $queriedColumns = [], SQLSelect $sqlSelect) { // Get metadata and SQL from join table $hasManyRelation = $this->getParentRelationship($dataQuery); $joinTableSQLSelect = $hasManyRelation->dataQuery()->query(); $joinTableSQL = $joinTableSQLSelect->sql($joinTableParameters); $joinTableColumns = array_keys($joinTableSQLSelect->getSelect()); // Get aliases (keys) only $joinTableAlias = $this->getJoinAlias(); // Get fields to join on $localKey = $this->getLocalKey(); $schema = DataObject::getSchema(); $baseTable = $schema->baseDataClass($dataQuery->dataClass()); $childField = $schema->sqlColumnForField($baseTable, 'ID'); // Add select fields foreach($joinTableColumns as $joinTableColumn) { $sqlSelect->selectField( "\"{$joinTableAlias}\".\"{$joinTableColumn}\"", "{$joinTableAlias}_{$joinTableColumn}" ); } // Apply join and record sql for later insertion (at end of replacements) $sqlSelect->addInnerJoin( '(SELECT $$_SUBQUERY_$$)', "\"{$joinTableAlias}\".\"{$localKey}\" = {$childField}", $joinTableAlias, 20, $joinTableParameters ); $dataQuery->setQueryParam('Foreign.JoinTableSQL', $joinTableSQL); // After this join, and prior to afterGetFinalisedQuery, $sqlSelect will be populated with the // necessary sql rewrites (versioned, etc) that effect the base table. // By using a placeholder for the subquery we can protect the subquery (already rewritten) // from being re-written a second time. However we DO want the join predicate (above) to be rewritten. // See http://php.net/manual/en/function.str-replace.php#refsect1-function.str-replace-notes // for the reason we only add the final substitution at the end of getFinalisedQuery() } /** * Invoked after getFinalisedQuery() * * @param DataQuery $dataQuery * @param array $queriedColumns * @param SQLSelect $sqlQuery */ public function afterGetFinalisedQuery(DataQuery $dataQuery, $queriedColumns = [], SQLSelect $sqlQuery) { // Inject final replacement after manipulation has been performed on the base dataquery $joinTableSQL = $dataQuery->getQueryParam('Foreign.JoinTableSQL'); if ($joinTableSQL) { $sqlQuery->replaceText('SELECT $$_SUBQUERY_$$', $joinTableSQL); $dataQuery->setQueryParam('Foreign.JoinTableSQL', null); } } }