allow creating PRIMARY KEY AUTOINCREMENT fields for sqlite

If a PRIMARY KEY field is defined in sqlite without autoincrement then
keys might be reused when rows are deleted, explicitly settings autoincrement
will prevent this.

Autoincrement is not enabled by default due to additional overhead introduced
with autoincrement bookkeeping and should only be enabled when the additional
uniqueness is required.

lib/Doctrine/DBAL/Platforms/SqlitePlatform.php

@@ -307,9 +307,9 @@ class SqlitePlatform extends AbstractPlatform
      */
     protected function _getCommonIntegerTypeDeclarationSQL(array $columnDef)
     {
-        // sqlite autoincrement is implicit for integer PKs, but not when the field is unsigned
+        // sqlite autoincrement is only possible for the primary key
         if ( ! empty($columnDef['autoincrement'])) {
-            return '';
+            return ' PRIMARY KEY AUTOINCREMENT';
         }
 
         return ! empty($columnDef['unsigned']) ? ' UNSIGNED' : '';
@@ -345,7 +345,10 @@ class SqlitePlatform extends AbstractPlatform
 
         if (isset($options['primary']) && ! empty($options['primary'])) {
             $keyColumns = array_unique(array_values($options['primary']));
-            $queryFields.= ', PRIMARY KEY('.implode(', ', $keyColumns).')';
+            // the primary key is already defined in the column definition for auto increment fields
+            if (count($keyColumns) > 1 || !$columns[$keyColumns[0]]['autoincrement']) {
+                $queryFields .= ', PRIMARY KEY(' . implode(', ', $keyColumns) . ')';
+            }
         }
 
         if (isset($options['foreignKeys'])) {

tests/Doctrine/Tests/DBAL/Functional/Schema/SqliteSchemaManagerTest.php

@@ -232,4 +232,63 @@ SQL;
             array('bigint', true, true),
         );
     }
+
+    /**
+     * @group DBAL-2921
+     */
+    public function testPrimaryKeyAutoIncrement()
+    {
+        $table = new Schema\Table('test_pk_auto_increment');
+        $table->addColumn('id', 'integer', [
+            'autoincrement' => true
+        ]);
+        $table->addColumn('text', 'text');
+        $table->setPrimaryKey(['id']);
+        $this->_sm->dropAndCreateTable($table);
+
+        $this->_conn->insert('test_pk_auto_increment', ['text' => '1']);
+        $this->_conn->insert('test_pk_auto_increment', ['text' => '2']);
+        $this->_conn->insert('test_pk_auto_increment', ['text' => '3']);
+
+        $query = $this->_conn->query('SELECT id FROM test_pk_auto_increment WHERE text = "3"');
+        $query->execute();
+        $lastUsedIdBeforeDelete = (int)$query->fetchColumn();
+
+        $this->_conn->query('DELETE FROM test_pk_auto_increment');
+
+        $this->_conn->insert('test_pk_auto_increment', ['text' => '4']);
+
+        $query = $this->_conn->query('SELECT id FROM test_pk_auto_increment WHERE text = "4"');
+        $query->execute();
+        $lastUsedIdAfterDelete = (int)$query->fetchColumn();
+
+        $this->assertGreaterThan($lastUsedIdBeforeDelete, $lastUsedIdAfterDelete);
+    }
+
+    /**
+     * @group DBAL-2921
+     */
+    public function testPrimaryKeyNoAutoIncrement()
+    {
+        $table = new Schema\Table('test_pk_auto_increment');
+        $table->addColumn('id', 'integer');
+        $table->addColumn('text', 'text');
+        $table->setPrimaryKey(['id']);
+        $this->_sm->dropAndCreateTable($table);
+
+        $this->_conn->insert('test_pk_auto_increment', ['text' => '1']);
+        $this->_conn->insert('test_pk_auto_increment', ['text' => '2']);
+        $this->_conn->insert('test_pk_auto_increment', ['text' => '3']);
+
+        $this->_conn->query('DELETE FROM test_pk_auto_increment');
+
+        $this->_conn->insert('test_pk_auto_increment', ['text' => '4']);
+
+        $query = $this->_conn->query('SELECT id FROM test_pk_auto_increment WHERE text = "4"');
+        $query->execute();
+        $lastUsedIdAfterDelete = (int)$query->fetchColumn();
+
+        // with an empty table, non autoincrement rowid is always 1
+        $this->assertEquals(1, $lastUsedIdAfterDelete);
+    }
 }