From 5bee607afb7dc02f451eea813dddc9d7ac21ba45 Mon Sep 17 00:00:00 2001
From: Mathieu Jaumotte <mathieu.jaumotte@champs-libres.coop>
Date: Fri, 2 Apr 2021 19:21:44 +0200
Subject: [PATCH] fix migration review: improve up and down query

---
 .../migrations/Version20210326113045.php      | 72 ++++---------------
 1 file changed, 15 insertions(+), 57 deletions(-)

diff --git a/src/Bundle/ChillPersonBundle/migrations/Version20210326113045.php b/src/Bundle/ChillPersonBundle/migrations/Version20210326113045.php
index 5113ccce2..68ad31667 100644
--- a/src/Bundle/ChillPersonBundle/migrations/Version20210326113045.php
+++ b/src/Bundle/ChillPersonBundle/migrations/Version20210326113045.php
@@ -23,26 +23,8 @@ final class Version20210326113045 extends AbstractMigration
     }
     
     /**
-     *  === UP ===>
-     *
-     *  Preup and postup functions backup datas and transform them
-     *  before injecting them in the new many-to-many join table.
      *  In these direction, there is no loss.
      */
-    public function preUp(Schema $schema) : void
-    {
-        // extract datas
-        $query = "SELECT person_id, id as accompagnying_period_id FROM chill_person_accompanying_period WHERE person_id IS NOT NULL";
-        $data = $this->connection->prepare($query);
-        $data->execute();
-        foreach ($data as $row)
-        {
-            $personId = $row['person_id'];
-            $accompagnyingPeriodId = $row['accompagnying_period_id'];
-            $this->datas[] = "($personId, $accompagnyingPeriodId)";
-        }
-    }
-    
     public function up(Schema $schema) : void
     {
         // create join table
@@ -51,6 +33,10 @@ final class Version20210326113045 extends AbstractMigration
         $this->addSql('CREATE INDEX IDX_49A3871F550B0C53 ON persons_accompanying_periods (accompanyingperiod_id)');
         $this->addSql('ALTER TABLE persons_accompanying_periods ADD CONSTRAINT FK_49A3871F217BBB47 FOREIGN KEY (person_id) REFERENCES chill_person_person (id) ON DELETE CASCADE NOT DEFERRABLE INITIALLY IMMEDIATE');
         $this->addSql('ALTER TABLE persons_accompanying_periods ADD CONSTRAINT FK_49A3871F550B0C53 FOREIGN KEY (accompanyingperiod_id) REFERENCES chill_person_accompanying_period (id) ON DELETE CASCADE NOT DEFERRABLE INITIALLY IMMEDIATE');
+    
+        // insert datas in new join table
+        $this->addSql('INSERT INTO persons_accompanying_periods (person_id, accompanyingperiod_id)'
+            . 'SELECT person_id, id as accompagnying_period_id FROM chill_person_accompanying_period WHERE person_id IS NOT NULL');
         
         // drop column
         $this->addSql('DROP INDEX idx_64a4a621217bbb47');
@@ -58,55 +44,27 @@ final class Version20210326113045 extends AbstractMigration
         $this->addSql('ALTER TABLE chill_person_accompanying_period DROP person_id');
     }
     
-    public function postUp(Schema $schema) : void
-    {
-        // insert datas in new join table
-        $SQL = "INSERT INTO persons_accompanying_periods (person_id, accompanyingperiod_id) VALUES " . implode(', ', $this->datas);
-        $this->connection->executeQuery($SQL);
-    }
-    
-    
     /**
-     *  <=== DOWN ===
-     *
-     *  In predown and postdown we backup datas from jointable, and transform them
-     *  before injecting them back in the many-to-one column 'person_id'.
-     *
      *  The distinct clause makes that for each group of duplicates, it keeps only the first row in the returned result set.
      *  Then we have only few lost datas. Lost datas: when many persons for one AccompanyingPeriod (keep only first person)
      */
-    
-    public function preDown(Schema $schema) : void
-    {
-        // extract datas
-        $query = "SELECT DISTINCT ON (accompanyingperiod_id) accompanyingperiod_id AS id, person_id FROM persons_accompanying_periods ORDER BY id, person_id ASC";
-        $data = $this->connection->prepare($query);
-        $data->execute();
-        foreach ($data as $row)
-        {
-            $id = $row['id'];
-            $personId = $row['person_id'];
-            $this->datas[$id] = "$personId";
-        }
-    }
-    
     public function down(Schema $schema) : void
     {
-        // drop join table
-        $this->addSql('DROP TABLE persons_accompanying_periods');
-        
         // add column
         $this->addSql('ALTER TABLE chill_person_accompanying_period ADD person_id INT DEFAULT NULL');
         $this->addSql('ALTER TABLE chill_person_accompanying_period ADD CONSTRAINT fk_64a4a621217bbb47 FOREIGN KEY (person_id) REFERENCES chill_person_person (id) NOT DEFERRABLE INITIALLY IMMEDIATE');
         $this->addSql('CREATE INDEX idx_64a4a621217bbb47 ON chill_person_accompanying_period (person_id)');
-    }
-    
-    public function postDown(Schema $schema) : void
-    {
+
         // insert datas in existing table
-        foreach ($this->datas as $id => $personId) {
-            $SQL = "UPDATE chill_person_accompanying_period SET person_id='$personId' WHERE id='$id'";
-            $this->connection->executeQuery($SQL); // CHECK if we have to execute query out of foreach loop. how ?
-        }
+        $this->addSql('UPDATE chill_person_accompanying_period AS ap '
+            . 'SET person_id = jt.person_id '
+            . 'FROM ( '
+            .   'SELECT DISTINCT ON (accompanyingperiod_id) accompanyingperiod_id AS id, person_id FROM persons_accompanying_periods '
+            .   'ORDER BY id, person_id ASC '
+            . ') AS jt '
+            . 'WHERE ap.id = jt.id');
+        
+        // drop join table
+        $this->addSql('DROP TABLE persons_accompanying_periods');
     }
 }