make left joins really work

src/PersistentData/PersistentDataManager.php

@@ -148,10 +148,9 @@ class PersistentDataManager implements IPersistentDataManager
                 $relations = array_intersect_key($relations, array_flip($withRelations));
             }
 
-            $columns = array_merge($columns, $this->getRelationColumns($relations, $withRelations));
+            $columns = array_merge($columns, $this->getRelationColumns($table, $relations, $withRelations));
 
-            $alreadyUsedTableAliases = [$table => true];
-            $this->leftJoinRelations($select, $table, $relations, $withRelations, $alreadyUsedTableAliases);
+            $this->leftJoinRelations($select, $table, $relations, $withRelations);
             $select->columns($columns);
         } else {
             $select->columns($columns);
@@ -160,59 +159,43 @@ class PersistentDataManager implements IPersistentDataManager
         return $select;
     }
 
-    private function getRelationColumns(array $relations, array $withRelations): array
+    private function getRelationColumns(string $table, array $relations, array $withRelations): array
     {
         $columns = [];
 
         foreach ($relations as $relation => $relationType) {
+            $relationTableAlias = $table . '__' . $relation;
             $relationTable = call_user_func([$relationType, 'getTable']);
             foreach (call_user_func([$relationType, 'getFields']) as $relationField) {
-                $columns[] = [$relationTable, $relationField, $relation . '__' . $relationField];
+                $columns[] = [$relationTableAlias, $relationField, $relation . '__' . $relationField];
             }
 
             $relationsOfRelation = call_user_func([$relationType, 'getRelations']);
             if (count($withRelations)) {
                 $relationsOfRelation = array_intersect_key($relationsOfRelation, array_flip($withRelations));
             }
-            $columns = array_merge($columns, $this->getRelationColumns($relationsOfRelation, $withRelations));
+            $columns = array_merge($columns, $this->getRelationColumns($relationTable, $relationsOfRelation, $withRelations));
         }
 
         return $columns;
     }
 
-    private function leftJoinRelations(Select $select, string $table, array $relations, array $withRelations, array &$alreadyUsedTableAliases): void
+    private function leftJoinRelations(Select $select, string $table, array $relations, array $withRelations): void
     {
         foreach ($relations as $relation => $relationType) {
-            $relationTable = $this->generateTableAlias($select, call_user_func([$relationType, 'getTable']), $alreadyUsedTableAliases);
-            $select->leftJoin($relationTable, [$relationTable, 'id'], '=', [$table, $relation . '_id']);
+            $relationTableAlias = $table . '__' . $relation;
+            $relationTable = call_user_func([$relationType, 'getTable']);
+            $select->setTableAliases([$relationTableAlias => $relationTable]);
+            $select->leftJoin($relationTableAlias, [$relationTableAlias, 'id'], '=', [$table, $relation . '_id']);
 
             $relationsOfRelation = call_user_func([$relationType, 'getRelations']);
             if (count($withRelations)) {
                 $relationsOfRelation = array_intersect_key($relationsOfRelation, array_flip($withRelations));
             }
-            $this->leftJoinRelations($select, $relationTable, $relationsOfRelation, $withRelations, $alreadyUsedTableAliases);
+            $this->leftJoinRelations($select, $relationTable, $relationsOfRelation, $withRelations);
         }
     }
 
-    private function generateTableAlias(Select $select, string $table, array &$alreadyUsedTableAliases)
-    {
-        if (!isset($alreadyUsedTableAliases[$table])) {
-            $alreadyUsedTableAliases[$table] = true;
-            return $table;
-        }
-
-        $i = 2;
-        do {
-            $alias = $table[0] . $i;
-            $i++;
-        } while (isset($alreadyUsedTableAliases[$alias]));
-
-        $select->setTableAliases([$alias => $table]);
-        $alreadyUsedTableAliases[$alias] = true;
-
-        return $alias;
-    }
-
     private function fillWithData(array &$data, Model $model, array $withRelations = [], ?string $modelKey = null): void
     {
         $relations = $model::getRelations();
@@ -244,12 +227,16 @@ class PersistentDataManager implements IPersistentDataManager
 
                 next($data);
             } else if (substr($key, 0, strlen($relation . '__')) === $relation . '__') {
-                $relationType = current($relations);
-                $relationModel = new $relationType();
-                $this->fillWithData($data, $relationModel, $withRelations, $relation);
+                if ($data[$relation . '__id'] !== null) {
+                    $relationType = current($relations);
+                    $relationModel = new $relationType();
+                    $this->fillWithData($data, $relationModel, $withRelations, $relation);
 
-                $method = 'set' . str_replace('_', '', ucwords($relation, '_'));
-                $model->$method($relationModel);
+                    $method = 'set' . str_replace('_', '', ucwords($relation, '_'));
+                    $model->$method($relationModel);
+                } else {
+                    next($data);
+                }
 
                 next($relations);
             } else {