src/Illuminate/Database/Eloquent/Relations/Concerns/CanBeOneOfMany.php
<?php
namespace Illuminate\Database\Eloquent\Relations\Concerns;
use Closure;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Query\JoinClause;
use Illuminate\Support\Arr;
use InvalidArgumentException;
trait CanBeOneOfMany
{
/**
* Determines whether the relationship is one-of-many.
*
* @var bool
*/
protected $isOneOfMany = false;
/**
* The name of the relationship.
*
* @var string
*/
protected $relationName;
/**
* The one of many inner join subselect query builder instance.
*
* @var \Illuminate\Database\Eloquent\Builder|null
*/
protected $oneOfManySubQuery;
/**
* Add constraints for inner join subselect for one of many relationships.
*
* @param \Illuminate\Database\Eloquent\Builder $query
* @param string|null $column
* @param string|null $aggregate
* @return void
*/
abstract public function addOneOfManySubQueryConstraints(Builder $query, $column = null, $aggregate = null);
/**
* Get the columns the determine the relationship groups.
*
* @return array|string
*/
abstract public function getOneOfManySubQuerySelectColumns();
/**
* Add join query constraints for one of many relationships.
*
* @param \Illuminate\Database\Query\JoinClause $join
* @return void
*/
abstract public function addOneOfManyJoinSubQueryConstraints(JoinClause $join);
/**
* Indicate that the relation is a single result of a larger one-to-many relationship.
*
* @param string|array|null $column
* @param string|\Closure|null $aggregate
* @param string|null $relation
* @return $this
*
* @throws \InvalidArgumentException
*/
public function ofMany($column = 'id', $aggregate = 'MAX', $relation = null)
{
$this->isOneOfMany = true;
$this->relationName = $relation ?: $this->getDefaultOneOfManyJoinAlias(
$this->guessRelationship()
);
$keyName = $this->query->getModel()->getKeyName();
$columns = is_string($columns = $column) ? [
$column => $aggregate,
$keyName => $aggregate,
] : $column;
if (! array_key_exists($keyName, $columns)) {
$columns[$keyName] = 'MAX';
}
if ($aggregate instanceof Closure) {
$closure = $aggregate;
}
foreach ($columns as $column => $aggregate) {
if (! in_array(strtolower($aggregate), ['min', 'max'])) {
throw new InvalidArgumentException("Invalid aggregate [{$aggregate}] used within ofMany relation. Available aggregates: MIN, MAX");
}
$subQuery = $this->newOneOfManySubQuery(
$this->getOneOfManySubQuerySelectColumns(),
array_merge([$column], $previous['columns'] ?? []),
$aggregate,
);
if (isset($previous)) {
$this->addOneOfManyJoinSubQuery(
$subQuery,
$previous['subQuery'],
$previous['columns'],
);
}
if (isset($closure)) {
$closure($subQuery);
}
if (! isset($previous)) {
$this->oneOfManySubQuery = $subQuery;
}
if (array_key_last($columns) == $column) {
$this->addOneOfManyJoinSubQuery(
$this->query,
$subQuery,
array_merge([$column], $previous['columns'] ?? []),
);
}
$previous = [
'subQuery' => $subQuery,
'columns' => array_merge([$column], $previous['columns'] ?? []),
];
}
$this->addConstraints();
$columns = $this->query->getQuery()->columns;
if (is_null($columns) || $columns === ['*']) {
$this->select([$this->qualifyColumn('*')]);
}
return $this;
}
/**
* Indicate that the relation is the latest single result of a larger one-to-many relationship.
*
* @param string|array|null $column
* @param string|null $relation
* @return $this
*/
public function latestOfMany($column = 'id', $relation = null)
{
return $this->ofMany(collect(Arr::wrap($column))->mapWithKeys(function ($column) {
return [$column => 'MAX'];
})->all(), 'MAX', $relation);
}
/**
* Indicate that the relation is the oldest single result of a larger one-to-many relationship.
*
* @param string|array|null $column
* @param string|null $relation
* @return $this
*/
public function oldestOfMany($column = 'id', $relation = null)
{
return $this->ofMany(collect(Arr::wrap($column))->mapWithKeys(function ($column) {
return [$column => 'MIN'];
})->all(), 'MIN', $relation);
}
/**
* Get the default alias for the one of many inner join clause.
*
* @param string $relation
* @return string
*/
protected function getDefaultOneOfManyJoinAlias($relation)
{
return $relation == $this->query->getModel()->getTable()
? $relation.'_of_many'
: $relation;
}
/**
* Get a new query for the related model, grouping the query by the given column, often the foreign key of the relationship.
*
* @param string|array $groupBy
* @param array<string>|null $columns
* @param string|null $aggregate
* @return \Illuminate\Database\Eloquent\Builder
*/
protected function newOneOfManySubQuery($groupBy, $columns = null, $aggregate = null)
{
$subQuery = $this->query->getModel()
->newQuery()
->withoutGlobalScopes($this->removedScopes());
foreach (Arr::wrap($groupBy) as $group) {
$subQuery->groupBy($this->qualifyRelatedColumn($group));
}
if (! is_null($columns)) {
foreach ($columns as $key => $column) {
$aggregatedColumn = $subQuery->getQuery()->grammar->wrap($subQuery->qualifyColumn($column));
if ($key === 0) {
$aggregatedColumn = "{$aggregate}({$aggregatedColumn})";
} else {
$aggregatedColumn = "min({$aggregatedColumn})";
}
$subQuery->selectRaw($aggregatedColumn.' as '.$subQuery->getQuery()->grammar->wrap($column.'_aggregate'));
}
}
$this->addOneOfManySubQueryConstraints($subQuery, $groupBy, $columns, $aggregate);
return $subQuery;
}
/**
* Add the join subquery to the given query on the given column and the relationship's foreign key.
*
* @param \Illuminate\Database\Eloquent\Builder $parent
* @param \Illuminate\Database\Eloquent\Builder $subQuery
* @param array<string> $on
* @return void
*/
protected function addOneOfManyJoinSubQuery(Builder $parent, Builder $subQuery, $on)
{
$parent->beforeQuery(function ($parent) use ($subQuery, $on) {
$subQuery->applyBeforeQueryCallbacks();
$parent->joinSub($subQuery, $this->relationName, function ($join) use ($on) {
foreach ($on as $onColumn) {
$join->on($this->qualifySubSelectColumn($onColumn.'_aggregate'), '=', $this->qualifyRelatedColumn($onColumn));
}
$this->addOneOfManyJoinSubQueryConstraints($join, $on);
});
});
}
/**
* Merge the relationship query joins to the given query builder.
*
* @param \Illuminate\Database\Eloquent\Builder $query
* @return void
*/
protected function mergeOneOfManyJoinsTo(Builder $query)
{
$query->getQuery()->beforeQueryCallbacks = $this->query->getQuery()->beforeQueryCallbacks;
$query->applyBeforeQueryCallbacks();
}
/**
* Get the query builder that will contain the relationship constraints.
*
* @return \Illuminate\Database\Eloquent\Builder
*/
protected function getRelationQuery()
{
return $this->isOneOfMany()
? $this->oneOfManySubQuery
: $this->query;
}
/**
* Get the one of many inner join subselect builder instance.
*
* @return \Illuminate\Database\Eloquent\Builder|void
*/
public function getOneOfManySubQuery()
{
return $this->oneOfManySubQuery;
}
/**
* Get the qualified column name for the one-of-many relationship using the subselect join query's alias.
*
* @param string $column
* @return string
*/
public function qualifySubSelectColumn($column)
{
return $this->getRelationName().'.'.last(explode('.', $column));
}
/**
* Qualify related column using the related table name if it is not already qualified.
*
* @param string $column
* @return string
*/
protected function qualifyRelatedColumn($column)
{
return str_contains($column, '.') ? $column : $this->query->getModel()->getTable().'.'.$column;
}
/**
* Guess the "hasOne" relationship's name via backtrace.
*
* @return string
*/
protected function guessRelationship()
{
return debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 3)[2]['function'];
}
/**
* Determine whether the relationship is a one-of-many relationship.
*
* @return bool
*/
public function isOneOfMany()
{
return $this->isOneOfMany;
}
/**
* Get the name of the relationship.
*
* @return string
*/
public function getRelationName()
{
return $this->relationName;
}
}