Php – Delete records in Doctrine

doctrinedoctrine-ormPHPsymfony

I'm trying to delete a record in Doctrine, but I don't know why it's not deleting.

Here is my Code:

function del_user($id)
{
    $single_user = $entityManager->find('Users', $id);

    $entityManager->remove($single_user);

    $entityManager->flush();
}

Plus: How can I echo query to see what going on here?

Best Answer

This is an old question and doesn't seem to have an answer yet. For reference I am leaving that here for more reference. Also you can check the doctrine documentation

To delete a record, you need to ( assuming you are in your controller ):

// get EntityManager
$em = $this->getDoctrine()->getManager();

// Get a reference to the entity ( will not generate a query )
$user = $em->getReference('ProjectBundle:User', $id);

// OR you can get the entity itself ( will generate a query )
// $user = $em->getRepository('ProjectBundle:User')->find($id);

// Remove it and flush
$em->remove($user);
$em->flush();

Using the first method of getting a reference is usually better if you just want to delete the entity without checking first whether it exists or not, because it will not query the DB and will only create a proxy object that you can use to delete your entity.

If you want to make sure that this ID corresponds to a valid entity first, then the second method is better because it will query the DB for your entity before trying to delete it.

Related Solutions

Php – Reference — What does this symbol mean in PHP

Incrementing / Decrementing Operators

++ increment operator

-- decrement operator

Example    Name              Effect
---------------------------------------------------------------------
++$a       Pre-increment     Increments $a by one, then returns $a.
$a++       Post-increment    Returns $a, then increments $a by one.
--$a       Pre-decrement     Decrements $a by one, then returns $a.
$a--       Post-decrement    Returns $a, then decrements $a by one.

These can go before or after the variable.

If put before the variable, the increment/decrement operation is done to the variable first then the result is returned. If put after the variable, the variable is first returned, then the increment/decrement operation is done.

For example:

$apples = 10;
for ($i = 0; $i < 10; ++$i) {
    echo 'I have ' . $apples-- . " apples. I just ate one.\n";
}

Live example

In the case above ++$i is used, since it is faster. $i++ would have the same results.

Pre-increment is a little bit faster because it really increments the variable and after that 'returns' the result. Post-increment creates a special variable, copies there the value of the first variable and only after the first variable is used, replaces its value with second's.

However, you must use $apples--, since first, you want to display the current number of apples, and then you want to subtract one from it.

You can also increment letters in PHP:

$i = "a";
while ($i < "c") {
    echo $i++;
}

Once z is reached aa is next, and so on.

Note that character variables can be incremented but not decremented and even so only plain ASCII characters (a-z and A-Z) are supported.

Stack Overflow Posts:

Understanding Incrementing

Php – On delete cascade with doctrine2

There are two kinds of cascades in Doctrine:

1) ORM level - uses cascade={"remove"} in the association - this is a calculation that is done in the UnitOfWork and does not affect the database structure. When you remove an object, the UnitOfWork will iterate over all objects in the association and remove them.

2) Database level - uses onDelete="CASCADE" on the association's joinColumn - this will add On Delete Cascade to the foreign key column in the database:

@ORM\JoinColumn(name="father_id", referencedColumnName="id", onDelete="CASCADE")

I also want to point out that the way you have your cascade={"remove"} right now, if you delete a Child object, this cascade will remove the Parent object. Clearly not what you want.

Best Answer

Related Solutions

Php – Reference — What does this symbol mean in PHP

Php – On delete cascade with doctrine2

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