I have a difficult problem and I don’t know how to do it.
I want to archive some objects and then delete them from the initial tables. The problem is that these objects are connected to each other. I have code that is close to work, but I think this is not a clean way to do this. It consists of SQL queries that copy rows with their identifiers into new tables. Another problem is that I do not need fields for archiving, so the archive objects are not exactly the same as the original ones. I am using a raw SQL query and not DQL due to the size of my tables.
I want to back up these objects: Colle, ColleQC, QC, PasserColle, Reponse, ReponseQC, StatistiqueColle, StatistiqueQuestion, RepartitionColle, RepartitionQuestion, Tuteur By BanqueColle, BanqueColleQC, BanqueQC, BanquePasserColle, BanqueReponse, BanqueReponseQC, BanqueStatistiqueColle, BanqueStatistiqueQuestion, BanqueRepartitionColle, BanqueRepartitionQuestion, AncienAdherent.
I will use this archive for another part of my application.
Example table structure: 
(Tuteur and AncienAdherent extend the user)
Here is the part of the code that I did for archiving, but I don't think this is a clean way to do this:
public function archiveTuteurs() {
$db = $this->em->getConnection();
$query = "INSERT INTO ancien_adherent (id)
SELECT u.id
FROM user u
WHERE discr = 'tuteur'";
$stmt = $db->prepare($query);
$stmt->execute();
$query2 = "UPDATE user
SET user.discr = 'ancien'
WHERE discr = 'tuteur'";
$stmt = $db->prepare($query2);
$stmt->execute();
return true;
}
public function archiveColles() {
$db = $this->em->getConnection();
$query = "INSERT INTO banque_colle (id, typeColle, nom, temps_epreuve, matiere_id, dateCreation, ordre, discr)
SELECT colle.id, colle.typeColle, colle.nom, colle.temps_epreuve, colle.matiere_id, colle.dateCreation, colle.ordre, colle.discr
FROM colle";
$stmt = $db->prepare($query);
$stmt->execute();
$query2 = "INSERT INTO banque_colle_qc (id)
SELECT colle_qc.id
FROM colle_qc";
$stmt = $db->prepare($query2);
$stmt->execute();
return true;
}
public function archiveQC() {
$db = $this->em->getConnection();
$query = "INSERT INTO banque_qc (id, titre, id_colle, ordre, qcPere, enonce, donnees, item1, item2, item3, item4,
item5, corrige_item1, corrige_item2, corrige_item3, corrige_item4, corrige_item5, item1_vrai,
item2_vrai, item3_vrai, item4_vrai, item5_vrai, item1_annule, item2_annule, item3_annule,
item4_annule, item5_annule, multiple_choices, inclu)
SELECT qc.id, qc.titre, qc.id_colle, qc.ordre, qc.qcPere, qc.enonce, qc.donnees, qc.item1, qc.item2,
qc.item3, qc.item4, qc.item5, qc.corrige_item1, qc.corrige_item2, qc.corrige_item3, qc.corrige_item4,
qc.corrige_item5, qc.item1_vrai, qc.item2_vrai, qc.item3_vrai, qc.item4_vrai, qc.item5_vrai,
qc.item1_annule, qc.item2_annule, qc.item3_annule, qc.item4_annule, qc.item5_annule,
qc.multiple_choices, qc.inclu
FROM qc
ORDER BY qc.qcPere ASC";
$stmt = $db->prepare($query);
$stmt->execute();
return true;
}
public function archivePassages() {
$db = $this->em->getConnection();
$query = "INSERT INTO banque_passer_colle (colle_id, dateDebut, note)
SELECT passer_colle.colle_id, passer_colle.dateDebut, passer_colle.note
FROM passer_colle";
$stmt = $db->prepare($query);
$stmt->execute();
return true;
}
public function archiveReponses() {
$db = $this->em->getConnection();
$query = "INSERT INTO banque_reponse (id, discr)
SELECT reponse.id, reponse.discr
FROM reponse
WHERE discr='reponseQC'";
$stmt = $db->prepare($query);
$stmt->execute();
$query2 = "INSERT INTO banque_reponse_qc (id, question, A, B, C, D, E, note)
SELECT reponse_qc.id, reponse_qc.question, reponse_qc.A, reponse_qc.B, reponse_qc.C, reponse_qc.D,
reponse_qc.E, reponse_qc.note
FROM reponse_qc";
$stmt = $db->prepare($query2);
$stmt->execute();
return true;
}
public function archiveStats() {
$db = $this->em->getConnection();
$query = "INSERT INTO banque_statistiquecolle (id, colle_id, effectif, moyenne, mediane, note100, major, minor)
SELECT sc.id, sc.colle_id, sc.effectif, sc.moyenne, sc.mediane, sc.note100, sc.major, sc.minor
FROM statistiquecolle_groupe scg
LEFT JOIN statistiquecolle sc ON sc.id = scg.statistiquecolle_id
WHERE scg.groupe_id = 1
AND sc.id NOT IN (SELECT sc1.id
FROM statistiquecolle_groupe scg1
LEFT JOIN statistiquecolle sc1 ON sc1.id = scg1.statistiquecolle_id
WHERE scg1.groupe_id != 1)";
$stmt = $db->prepare($query);
$stmt->execute();
$query2 = "INSERT INTO banque_statistiquequestion (id, question_id, moyenne, nbReponseTot, nbReponseA, nbReponseB,
nbReponseC, nbReponseD, nbReponseE)
SELECT sq.id, sq.question_id, sq.moyenne, sq.nbReponseTot, sq.nbReponseA, sq.nbReponseB, sq.nbReponseC,
sq.nbReponseD, sq.nbReponseE
FROM statistiquequestion_groupe sqg
LEFT JOIN statistiquequestion sq ON sq.id = sqg.statistiquequestion_id
WHERE sqg.groupe_id = 1
AND sq.id NOT IN (SELECT sq1.id
FROM statistiquequestion_groupe sqg1
LEFT JOIN statistiquequestion sq1 ON sq1.id = sqg1.statistiquequestion_id
WHERE sqg1.groupe_id != 1)";
$stmt = $db->prepare($query2);
$stmt->execute();
$query3 = "INSERT INTO banque_repartitioncolle (id, statColle_id, note, nombre, percentOfEffectif)
SELECT rc.id, rc.statColle_id, rc.note, rc.nombre, rc.percentOfEffectif
FROM repartitioncolle rc
WHERE rc.statColle_id IN (SELECT bsc.id
FROM banque_statistiquecolle bsc)";
$stmt = $db->prepare($query3);
$stmt->execute();
$query4 = "INSERT INTO banque_repartitionquestion (id, statQuestion_id, note, nombre, percentOfEffectif)
SELECT rq.id, rq.statQuestion_id, rq.note, rq.nombre, rq.percentOfEffectif
FROM repartitionquestion rq
WHERE rq.statQuestion_id IN (SELECT bsq.id
FROM banque_statistiquequestion bsq)";
$stmt = $db->prepare($query4);
$stmt->execute();
return true;
}