Doctrine Query Base with grouping and latest record - php

Question

I have a table "table_b" that contain the following details
I would like to use doctrine to query an output with a specific condition. Currently I'm using the block below to query.
$table_a= $em->getRepository('table_a')->findOneBy(['id'=>1]);
foreach($table_a->table_b as $records){
echo $records->name. " : " . $records->value;
}
It will output the entire ArrayCollection. Is there a way to query the record base on latest 'Date Created', that is base on the grouping of column 'Foreign Key Table 2'.

Answer 1

If you want to use native Doctrine query methods, you should use findOneBy with the order byparameter.
findOneBy(['id' => 1], ['DateCreated' => 'desc'])
Then, you says the result is an ArrayCollection, so using the ArrayCollection::first() method, you'll get the last created element
EDIT
Imagine you have a Group entity and a Member entity. groups table is your table_a and members table is your table_b.
Entity description should be something like that :
class Group
{
...
/**
* #ORM\OneToMany(targetEntity="Group", mappedBy="member", cascade={"persist", "remove", "merge"})
* #ORM\OrderBy({"dateCreated"="DESC"})
*/
protected $members;
...
public function __construct()
{
$members = new ArrayCollection();
}
// members handling accessors
/**
* #return ArrayCollection
*/
public function getMembers()
{
return $this->members;
}
/**
* #param $members
*
* #return $this
*/
public function setMembers($members)
{
$this->members = new ArrayCollection();
return $this->addMembers($members);
}
/**
* #param $members
*
* #return $this
*/
public function addMembers($members)
{
foreach ($members as $member)
{
$this->addMember($member);
}
return $this;
}
/**
* #param Member $member
*
* #return $this
*/
public function addMember(Member $member)
{
$this->members->add($member);
$member->setGroup($this);
return $this;
}
/**
* #param Member $member
*
* #return $this
*/
public function removeMember(Member $member)
{
if ($this->members->contains($member))
{
$this->members->removeElement($member);
}
return $this;
}
/**
* #param $members
*
* #return $this
*/
public function removeMembers($members)
{
foreach ($members as $member)
{
$this->removeMember($member);
}
return $this;
}
}
And Member entity :
class Member
{
/**
* #ORM\ManyToOne(targetEntity="Group", inversedBy="members")
* #ORM\JoinColumn(name="group_id", referencedColumnName="id", onDelete="CASCADE")
*/
protected $group;
/**
* #ORM\Column(type="datetime", name="date_created")
*/
protected $dateCreated;
/**
* #return Group
*/
public function getGroup()
{
return $this->group;
}
/**
* #param Group $group
*
* #return $this
*/
public function setGroup(Group $group)
{
$this->group = $group;
return $this;
}
}
Now, we have one group with a dateCreated ordered collection of members.
Example 1 : You want to get the last member created for a given group
$group = $em->getRepository(Group::class)->findOneBy(['id' => 1]);
$lastMember = $group->getMembers()->first();
Example 2 : You want to get all members created on 2014-01-30 :
$members = $group->getMembers()->filter(function (Member $member) {
return ($member->getDateCreated->format('Y-m-d') == '2014-01-30');
});
That's all folk !
PS : I haven't test this code

Answer 2

In TableRepository:
public function getLatestRecord()
{
return $this->getEntityManager()
->createQuery('SELECT t FROM MyBundle:MyEntity t GROUP BY t.table2NameField ORDER BY t.created DESC')
->setMaxResults(1)
->getOneOrNullResult();
}