Fix foreign keys

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## 1.0.2 under development
 
-- no changes in this release.
+- Bug #268: Fix foreign keys: support multiple foreign keys referencing to one table and possible null columns for reference (@Tigrov)
 
 ## 1.0.1 July 24, 2023
 

src/Schema.php

@@ -20,6 +20,7 @@
 use Yiisoft\Db\Schema\ColumnSchemaInterface;
 use Yiisoft\Db\Schema\TableSchemaInterface;
 
+use function array_column;
 use function array_merge;
 use function count;
 use function explode;
@@ -44,7 +45,7 @@
  *       seq:string,
  *       table:string,
  *       from:string,
- *       to:string,
+ *       to:string|null,
  *       on_update:string,
  *       on_delete:string
  *     }
@@ -58,7 +59,7 @@
  *     seq:string,
  *     table:string,
  *     from:string,
- *     to:string,
+ *     to:string|null,
  *     on_update:string,
  *     on_delete:string
  *   }
@@ -210,15 +211,35 @@ protected function loadTableForeignKeys(string $tableName): array
         DbArrayHelper::multisort($foreignKeysList, 'seq');
 
         /** @psalm-var NormalizePragmaForeignKeyList $foreignKeysList */
-        foreach ($foreignKeysList as $table => $foreignKey) {
-            $fk = (new ForeignKeyConstraint())
-                ->columnNames(DbArrayHelper::getColumn($foreignKey, 'from'))
-                ->foreignTableName($table)
-                ->foreignColumnNames(DbArrayHelper::getColumn($foreignKey, 'to'))
-                ->onDelete($foreignKey[0]['on_delete'] ?? null)
-                ->onUpdate($foreignKey[0]['on_update'] ?? null);
-
-            $result[] = $fk;
+        foreach ($foreignKeysList as $table => $foreignKeys) {
+            $foreignKeysById = DbArrayHelper::index($foreignKeys, null, ['id']);
+
+            /**
+             * @psalm-var NormalizePragmaForeignKeyList $foreignKeysById
+             * @psalm-var int $id
+             */
+            foreach ($foreignKeysById as $id => $foreignKey) {
+                if ($foreignKey[0]['to'] === null) {
+                    $primaryKey = $this->getTablePrimaryKey($table);
+
+                    if ($primaryKey !== null) {
+                        /** @psalm-var string $primaryKeyColumnName */
+                        foreach ((array) $primaryKey->getColumnNames() as $i => $primaryKeyColumnName) {
+                            $foreignKey[$i]['to'] = $primaryKeyColumnName;
+                        }
+                    }
+                }
+
+                $fk = (new ForeignKeyConstraint())
+                    ->name((string) $id)
+                    ->columnNames(array_column($foreignKey, 'from'))
+                    ->foreignTableName($table)
+                    ->foreignColumnNames(array_column($foreignKey, 'to'))
+                    ->onDelete($foreignKey[0]['on_delete'])
+                    ->onUpdate($foreignKey[0]['on_update']);
+
+                $result[] = $fk;
+            }
         }
 
         return $result;
@@ -380,19 +401,18 @@ protected function findColumns(TableSchemaInterface $table): bool
      */
     protected function findConstraints(TableSchemaInterface $table): void
     {
-        /** @psalm-var PragmaForeignKeyList $foreignKeysList */
-        $foreignKeysList = $this->getPragmaForeignKeyList($table->getName());
+        /** @psalm-var ForeignKeyConstraint[] $foreignKeysList */
+        $foreignKeysList = $this->getTableForeignKeys($table->getName(), true);
 
         foreach ($foreignKeysList as $foreignKey) {
-            $id = (int) $foreignKey['id'];
-            $fk = $table->getForeignKeys();
-
-            if (!isset($fk[$id])) {
-                $table->foreignKey($id, [$foreignKey['table'], $foreignKey['from'] => $foreignKey['to']]);
-            } else {
-                /** composite FK */
-                $table->compositeForeignKey($id, $foreignKey['from'], $foreignKey['to']);
-            }
+            /** @var array<string> $columnNames */
+            $columnNames = (array) $foreignKey->getColumnNames();
+            $columnNames = array_combine($columnNames, $foreignKey->getForeignColumnNames());
+
+            $foreignReference = array_merge([$foreignKey->getForeignTableName()], $columnNames);
+
+            /** @psalm-suppress InvalidCast */
+            $table->foreignKey((int) $foreignKey->getName(), $foreignReference);
         }
     }
 

src/TableSchema.php

@@ -11,6 +11,9 @@
  */
 final class TableSchema extends AbstractTableSchema
 {
+    /**
+     * @deprecated will be removed in version 2.0.0
+     */
     public function compositeForeignKey(int $id, string $from, string $to): void
     {
         $this->foreignKeys[$id][$from] = $to;

tests/Provider/SchemaProvider.php

@@ -392,7 +392,7 @@ public static function constraints(): array
         $constraints['2: unique'][2][0]->name(AnyValue::getInstance());
         $constraints['2: index'][2][2]->name(AnyValue::getInstance());
 
-        $constraints['3: foreign key'][2][0]->name(null);
+        $constraints['3: foreign key'][2][0]->name('0');
         $constraints['3: index'][2] = [];
 
         $constraints['4: primary key'][2]->name(null);

tests/SchemaTest.php

@@ -162,6 +162,33 @@ public function testForeingKey(): void
         $this->assertSame('NO ACTION', $foreingKeys[1]->getOnUpdate());
     }
 
+    public function testMultiForeingKeys(): void
+    {
+        $db = $this->getConnection(true);
+        $schema = $db->getSchema();
+        $tableSchema = $schema->getTableSchema('foreign_keys_child');
+
+        $this->assertNotNull($tableSchema);
+
+        $foreignKeys = $tableSchema->getForeignKeys();
+
+        $this->assertSame(
+            [
+                [
+                    'foreign_keys_parent',
+                    'y' => 'b',
+                    'z' => 'c',
+                ],
+                [
+                    'foreign_keys_parent',
+                    'x' => 'a',
+                    'y' => 'b',
+                ],
+            ],
+            $foreignKeys
+        );
+    }
+
     /**
      * @throws Exception
      * @throws InvalidConfigException
@@ -242,6 +269,9 @@ public function testGetTableForeignKeys(): void
         $this->assertSame(['C_id_1', 'C_id_2'], $tableForeingKeys[0]->getForeignColumnNames());
         $this->assertSame('CASCADE', $tableForeingKeys[0]->getOnDelete());
         $this->assertSame('CASCADE', $tableForeingKeys[0]->getOnUpdate());
+
+        $tableTwoForeignKeys = $schema->getTableForeignKeys('foreign_keys_child');
+        $this->assertCount(2, $tableTwoForeignKeys);
     }
 
     /**

tests/Support/Fixture/sqlite.sql

@@ -23,6 +23,8 @@ DROP TABLE IF EXISTS "T_constraints_1";
 DROP TABLE IF EXISTS "T_upsert";
 DROP TABLE IF EXISTS "T_upsert_1";
 DROP TABLE IF EXISTS "T_constraints_check";
+DROP TABLE IF EXISTS "foreign_keys_parent";
+DROP TABLE IF EXISTS "foreign_keys_child";
 
 CREATE TABLE "profile" (
   id INTEGER NOT NULL,
@@ -288,3 +290,21 @@ CREATE TABLE "T_constraints_check"
     "C_check_2" INT NOT NULL CHECK ("C_check_2" > 0),
     CONSTRAINT "CN_constraints_check" CHECK ("C_check_1" > "C_check_2")
 );
+
+CREATE TABLE foreign_keys_parent
+(
+    a INTEGER,
+    b INTEGER,
+    c INTEGER,
+    PRIMARY KEY(a, b),
+    UNIQUE (b, c)
+);
+
+CREATE TABLE foreign_keys_child
+(
+    x INTEGER,
+    y INTEGER,
+    z INTEGER,
+    FOREIGN KEY(x, y) REFERENCES foreign_keys_parent,
+    FOREIGN KEY(y, z) REFERENCES foreign_keys_parent(b, c)
+);