fix(SQLite): preserve indexes and foreign keys when altering an introspected table

src/Platforms/SQLitePlatform.php

@@ -837,6 +837,9 @@ private function getIndexesInAlteredTable(TableDiff $diff): array
             $changed      = false;
             $indexColumns = [];
             foreach ($index->getColumns() as $columnName) {
+                // the column names of an introspected index are quoted while the name map is keyed
+                // by the unquoted column names, so unquote before the lookup
+                $columnName           = (new Identifier($columnName))->getName();
                 $normalizedColumnName = strtolower($columnName);
                 if (! isset($nameMap[$normalizedColumnName])) {
                     unset($indexes[$key]);
@@ -904,6 +907,9 @@ private function getForeignKeysInAlteredTable(TableDiff $diff): array
             $changed      = false;
             $localColumns = [];
             foreach ($constraint->getLocalColumns() as $columnName) {
+                // the referencing column names of an introspected foreign key constraint are quoted
+                // while the name map is keyed by the unquoted column names, so unquote before the lookup
+                $columnName           = (new Identifier($columnName))->getName();
                 $normalizedColumnName = strtolower($columnName);
                 if (! isset($nameMap[$normalizedColumnName])) {
                     unset($foreignKeys[$key]);

tests/Functional/Schema/SQLiteSchemaManagerTest.php

@@ -9,8 +9,10 @@
 use Doctrine\DBAL\Platforms\SQLitePlatform;
 use Doctrine\DBAL\Schema\Column;
 use Doctrine\DBAL\Schema\ColumnDiff;
+use Doctrine\DBAL\Schema\ColumnEditor;
 use Doctrine\DBAL\Schema\ForeignKeyConstraint;
 use Doctrine\DBAL\Schema\Index;
+use Doctrine\DBAL\Schema\Index\IndexedColumn;
 use Doctrine\DBAL\Schema\Name\UnqualifiedName;
 use Doctrine\DBAL\Schema\PrimaryKeyConstraint;
 use Doctrine\DBAL\Schema\SQLiteSchemaManager;
@@ -26,6 +28,7 @@
 use function array_shift;
 use function array_values;
 use function assert;
+use function ksort;
 
 class SQLiteSchemaManagerTest extends SchemaManagerFunctionalTestCase
 {
@@ -316,6 +319,66 @@ public function testNonSimpleAlterTableCreatedFromDDL(): void
         self::assertSame(['name'], $index->getColumns());
     }
 
+    public function testAlterIntrospectedTablePreservesIndexesAndForeignKeys(): void
+    {
+        $this->dropTableIfExists('tree_nodes');
+
+        $ddl = <<<'DDL'
+        CREATE TABLE tree_nodes (
+            id        INTEGER NOT NULL,
+            parent_id INTEGER,
+            name      TEXT,
+            weight    INTEGER,
+            PRIMARY KEY (id),
+            FOREIGN KEY (parent_id) REFERENCES tree_nodes (id)
+        )
+        DDL;
+
+        $this->connection->executeStatement($ddl);
+        $this->connection->executeStatement('CREATE UNIQUE INDEX idx_tree_name ON tree_nodes (name)');
+        $this->connection->executeStatement('CREATE INDEX idx_tree_parent ON tree_nodes (parent_id)');
+
+        $schemaManager = $this->connection->createSchemaManager();
+
+        $oldTable = $schemaManager->introspectTableByUnquotedName('tree_nodes');
+        $newTable = $oldTable->edit()
+            ->modifyColumnByUnquotedName(
+                'weight',
+                static function (ColumnEditor $editor): void {
+                    $editor->setTypeName(Types::STRING)
+                        ->setLength(32);
+                },
+            )
+            ->create();
+
+        $diff = $schemaManager->createComparator()->compareTables($oldTable, $newTable);
+        $schemaManager->alterTable($diff);
+
+        $table = $schemaManager->introspectTableByUnquotedName('tree_nodes');
+
+        self::assertCount(1, $table->getForeignKeys());
+
+        $indexes = [];
+        foreach ($table->getIndexes() as $index) {
+            $indexName = $index->getObjectName()->getIdentifier()->getValue();
+            if ($indexName === 'primary') {
+                continue;
+            }
+
+            $indexes[$indexName] = array_map(
+                static fn (IndexedColumn $indexedColumn): string => $indexedColumn
+                    ->getColumnName()
+                    ->getIdentifier()
+                    ->getValue(),
+                $index->getIndexedColumns(),
+            );
+        }
+
+        ksort($indexes);
+
+        self::assertSame(['idx_tree_name' => ['name'], 'idx_tree_parent' => ['parent_id']], $indexes);
+    }
+
     public function testAlterTableWithSchema(): void
     {
         $this->dropTableIfExists('t');