/**
* Generates the join statement for many-many relationship.
* @param \Database\schema\TableSchema $joinTable the join table
* @param array $fks the foreign keys
* @param \Database\ActiveRecord\Join\Element $parent the parent join element
* @return string the join statement
* @throws \Exception if a foreign key is invalid
*/
private function joinManyMany($joinTable, $fks, $parent)
{
$schema = $this->_builder->getSchema();
$joinAlias = $schema->quoteTableName($this->relation->name . '_' . $this->tableAlias);
$parentCondition = [];
$childCondition = [];
$fkDefined = true;
foreach ($fks as $fk) {
if (!isset($joinTable->columns[$fk])) {
throw new \Database\Exception('The relation "{relation}" in active record class "{class}" is specified with an invalid foreign key "{key}". There is no such column in the table "{table}".', ['{class}' => get_class($parent->model), '{relation}' => $this->relation->name, '{key}' => $fk, '{table}' => $joinTable->name]);
}
if (isset($joinTable->foreignKeys[$fk])) {
list($tableName, $pk) = $joinTable->foreignKeys[$fk];
if (!isset($parentCondition[$pk]) && $schema->compareTableNames($parent->_table->rawName, $tableName)) {
$parentCondition[$pk] = $parent->getColumnPrefix() . $schema->quoteColumnName($pk) . '=' . $joinAlias . '.' . $schema->quoteColumnName($fk);
} elseif (!isset($childCondition[$pk]) && $schema->compareTableNames($this->_table->rawName, $tableName)) {
$childCondition[$pk] = $this->getColumnPrefix() . $schema->quoteColumnName($pk) . '=' . $joinAlias . '.' . $schema->quoteColumnName($fk);
} else {
$fkDefined = false;
break;
}
} else {
$fkDefined = false;
break;
}
}
if (!$fkDefined) {
$parentCondition = [];
$childCondition = [];
foreach ($fks as $i => $fk) {
if ($i < count($parent->_table->primaryKey)) {
$pk = is_array($parent->_table->primaryKey) ? $parent->_table->primaryKey[$i] : $parent->_table->primaryKey;
$parentCondition[$pk] = $parent->getColumnPrefix() . $schema->quoteColumnName($pk) . '=' . $joinAlias . '.' . $schema->quoteColumnName($fk);
} else {
$j = $i - count($parent->_table->primaryKey);
$pk = is_array($this->_table->primaryKey) ? $this->_table->primaryKey[$j] : $this->_table->primaryKey;
$childCondition[$pk] = $this->getColumnPrefix() . $schema->quoteColumnName($pk) . '=' . $joinAlias . '.' . $schema->quoteColumnName($fk);
}
}
}
if ($parentCondition !== [] && $childCondition !== []) {
$join = $this->relation->joinType . ' ' . $joinTable->rawName . ' ' . $joinAlias;
$join .= ' ON (' . implode(') AND (', $parentCondition) . ')';
$join .= ' ' . $this->relation->joinType . ' ' . $this->getTableNameWithAlias();
$join .= ' ON (' . implode(') AND (', $childCondition) . ')';
if (!empty($this->relation->on)) {
$join .= ' AND (' . $this->relation->on . ')';
}
return $join;
} else {
throw new \Database\Exception('The relation "{relation}" in active record class "{class}" is specified with an incomplete foreign key. The foreign key must consist of columns referencing both joining tables.', ['{class}' => get_class($parent->model), '{relation}' => $this->relation->name]);
}
}