diff --git a/ordigi.py b/ordigi.py
index 327b505..a2aa7bb 100755
--- a/ordigi.py
+++ b/ordigi.py
@@ -237,25 +237,63 @@ def clean(**kwargs):
         sys.exit(1)
 
 
-@click.command('generate-db')
+@click.command('init')
 @add_options(_logger_options)
-@click.option('--path', type=click.Path(file_okay=False),
-              required=True, help='Path of your photo library.')
-def generate_db(**kwargs):
+@click.argument('path', required=True, nargs=1, type=click.Path())
+def init(**kwargs):
     """Regenerate the hash.json database which contains all of the sha256 signatures of media files.
     """
-    # TODO
-    pass
+    config = Config(constants.CONFIG_FILE)
+    opt = config.get_options()
+    loc = GeoLocation(opt['geocoder'], opt['prefer_english_names'],
+            opt['timeout'])
+    debug = kwargs['debug']
+    verbose = kwargs['verbose']
+    logger = log.get_logger(debug, verbose)
+    collection = Collection(kwargs['path'], None, mode='move', logger=logger)
+    summary = collection.init(loc)
+    if verbose or debug:
+        summary.print()
 
 
-@click.command('verify')
+@click.command('update')
 @add_options(_logger_options)
-@click.option('--path', type=click.Path(file_okay=False),
-              required=True, help='Path of your photo library.')
-def verify(**kwargs):
-    """Verify hashes"""
-    # TODO
-    pass
+@click.argument('path', required=True, nargs=1, type=click.Path())
+def update(**kwargs):
+    """Regenerate the hash.json database which contains all of the sha256 signatures of media files.
+    """
+    config = Config(constants.CONFIG_FILE)
+    opt = config.get_options()
+    loc = GeoLocation(opt['geocoder'], opt['prefer_english_names'],
+            opt['timeout'])
+    debug = kwargs['debug']
+    verbose = kwargs['verbose']
+    logger = log.get_logger(debug, verbose)
+    collection = Collection(kwargs['path'], None, mode='move', logger=logger)
+    summary = collection.update(loc)
+    if verbose or debug:
+        summary.print()
+
+
+@click.command('check')
+@add_options(_logger_options)
+@click.argument('path', required=True, nargs=1, type=click.Path())
+def check(**kwargs):
+    """check db and verify hashes"""
+    debug = kwargs['debug']
+    verbose = kwargs['verbose']
+    logger = log.get_logger(debug, verbose)
+    collection = Collection(kwargs['path'], None, mode='move', logger=logger)
+    result = collection.check_db()
+    if result:
+        summary, result = collection.check_files()
+        if verbose or debug:
+            summary.print()
+        if not result:
+            sys.exit(1)
+    else:
+        self.logger.error('Db data is not accurate run `ordigi init`')
+        sys.exit(1)
 
 
 @click.command('compare')
@@ -317,10 +355,11 @@ def main(**kwargs):
 
 
 main.add_command(clean)
+main.add_command(check)
 main.add_command(compare)
+main.add_command(init)
 main.add_command(sort)
-main.add_command(generate_db)
-main.add_command(verify)
+main.add_command(update)
 
 
 if __name__ == '__main__':
diff --git a/ordigi/collection.py b/ordigi/collection.py
index 44d7ebb..ccd52cc 100644
--- a/ordigi/collection.py
+++ b/ordigi/collection.py
@@ -291,7 +291,7 @@ class Collection(object):
 
         return row_data
 
-    def _add_db_data(self, dest_path, metadata):
+    def _add_db_data(self, metadata):
         loc_values = self._format_row_data('location', metadata)
         metadata['location_id'] = self.db.add_row('location', loc_values)
 
@@ -334,7 +334,7 @@ class Collection(object):
 
                 media.metadata['file_path'] = os.path.relpath(dest_path,
                         self.root)
-                self._add_db_data(dest_path, media.metadata)
+                self._add_db_data(media.metadata)
                 if self.mode == 'move':
                     # Delete file path entry in db when file is moved inside collection
                     if str(self.root) in str(src_path):
@@ -655,6 +655,32 @@ class Collection(object):
         ]
         return inquirer.prompt(questions, theme=self.theme)['selection']
 
+    def _get_all_files(self):
+        return [x for x in self._get_files_in_path(self.root)]
+
+    def check_db(self):
+        """
+        Check if db FilePath match to collection filesystem
+        :returns: bool
+        """
+        file_paths = [x for x in self._get_all_files()]
+        db_rows = [row['FilePath'] for row in self.db.get_rows('metadata')]
+        for file_path in file_paths:
+            relpath = os.path.relpath(file_path, self.root)
+            # If file not in database
+            if relpath not in db_rows:
+                self.logger.error('Db data is not accurate')
+                self.logger.info(f'{file_path} not in db')
+                return False
+
+        nb_files = len(file_paths)
+        nb_row = len(db_rows)
+        if nb_row != nb_files:
+            self.logger.error('Db data is not accurate')
+            return False
+
+        return True
+
     def _check_processed(self):
         # Finally check if are files are successfully processed
         n_fail = len(self.src_list) - len(self.dest_list)
@@ -662,13 +688,86 @@ class Collection(object):
             self.logger.error("{n_fail} files have not be processed")
             return False
 
-        return True
+        return self.check_db()
+
+    def init(self, loc, ignore_tags=set()):
+        record = True
+        for file_path in self._get_all_files():
+            media = Media(file_path, self.root, ignore_tags=ignore_tags,
+                    logger=self.logger, use_date_filename=self.use_date_filename,
+                    use_file_dates=self.use_file_dates)
+            metadata = media.get_metadata(self.root, loc, self.db, self.cache)
+            media.metadata['file_path'] = os.path.relpath(file_path,
+                    self.root)
+            self._add_db_data(media.metadata)
+            self.summary.append((file_path, file_path))
+
+        return self.summary
+
+    def check_files(self):
+        result = True
+        for file_path in self._get_all_files():
+            checksum = utils.checksum(file_path)
+            relpath = file_path.relative_to(self.root)
+            if checksum == self.db.get_checksum(relpath):
+                self.summary.append((file_path, file_path))
+            else:
+                self.logger.error('{file_path} is corrupted')
+                self.summary.append((file_path, False))
+                result = False
+
+        return self.summary, result
+
+    def update(self, loc, ignore_tags=set()):
+        file_paths = [x for x in self._get_all_files()]
+        db_rows = [row for row in self.db.get_rows('metadata')]
+        invalid_db_rows = set()
+        for db_row in db_rows:
+            abspath = self.root / db_row['FilePath']
+            if abspath not in file_paths:
+                invalid_db_rows.add(db_row)
+
+        for file_path in file_paths:
+            relpath = os.path.relpath(file_path, self.root)
+            # If file not in database
+            if relpath not in db_rows:
+                media = Media(file_path, self.root, ignore_tags=ignore_tags,
+                        logger=self.logger, use_date_filename=self.use_date_filename,
+                        use_file_dates=self.use_file_dates)
+                metadata = media.get_metadata(self.root, loc, self.db, self.cache)
+                media.metadata['file_path'] = relpath
+                # Check if file checksum is in invalid rows
+                row = []
+                for row in invalid_db_rows:
+                    if row['Checksum'] == media.metadata['checksum']:
+                        # file have been moved without registering to db
+                        media.metadata['src_path'] = row['SrcPath']
+                        # Check if row FilePath is a subpath of relpath
+                        if relpath.startswith(row['FilePath']):
+                            d = os.path.relpath(relpath, row['FilePath'])
+                            media.metadata['subdirs'] = row['Subdirs'] + d
+                        media.metadata['Filename'] = row['Filename']
+                        break
+                # set row attribute to the file
+                self._add_db_data(media.metadata)
+                self.summary.append((file_path, file_path))
+
+        # Finally delete invalid rows
+        for row in invalid_db_rows:
+            self.db.delete_filepath(row['FilePath'])
+
+        return self.summary
 
     def sort_files(self, paths, loc, remove_duplicates=False,
             ignore_tags=set()):
         """
         Sort files into appropriate folder
         """
+        # Check db
+        if not self.check_db():
+            self.logger.error('Db data is not accurate run `ordigi init`')
+            sys.exit(1)
+
         result = False
         files_data = []
         for path in paths:
@@ -751,10 +850,16 @@ class Collection(object):
 
     def sort_similar_images(self, path, similarity=80):
 
+        # Check db
+        if not self.check_db():
+            self.logger.error('Db data is not accurate run `ordigi init`')
+            sys.exit(1)
+
         result = True
         path = self._check_path(path)
         images = set([ x for x in self._get_images(path) ])
         i = Images(images, logger=self.logger)
+        nb_row_ini = self.db.len('metadata')
         for image in images:
             if not image.img_path.is_file():
                 continue
@@ -794,14 +899,27 @@ class Collection(object):
                     self.summary.append((img_path, False))
                     result = False
 
+        nb_row_end = self.db.len('metadata')
+        if nb_row_ini and nb_row_ini != nb_row_end:
+            self.logger.error('Nb of row have changed unexpectedly')
+            result = False
+
+        if result:
+            result = self.check_db()
+
         return self.summary, result
 
     def revert_compare(self, path):
 
+        if not self.check_db():
+            self.logger.error('Db data is not accurate run `ordigi init`')
+            sys.exit(1)
+
         result = True
         path = self._check_path(path)
         dirnames = set()
         moved_files = set()
+        nb_row_ini = self.db.len('metadata')
         for src_path in self._get_files_in_path(path, glob=self.glob,
                 extensions=self.filter_by_ext):
             dirname = src_path.parent.name
@@ -827,6 +945,14 @@ class Collection(object):
             except OSError as error:
                 self.logger.error(error)
 
+        nb_row_end = self.db.len('metadata')
+        if nb_row_ini and nb_row_ini != nb_row_end:
+            self.logger.error('Nb of row have changed unexpectedly')
+            result = False
+
+        if result:
+            result = self.check_db()
+
         return self.summary, result
 
 
diff --git a/ordigi/database.py b/ordigi/database.py
index 414d1b6..066c01f 100644
--- a/ordigi/database.py
+++ b/ordigi/database.py
@@ -211,26 +211,26 @@ class Sqlite:
 
         return self.add_row(table, row_data)
 
-    def get_checksum(self, FilePath):
-        query = f"select Checksum from metadata where FilePath='{FilePath}'"
+    def get_checksum(self, file_path):
+        query = f"select Checksum from metadata where FilePath='{file_path}'"
         return self._run(query)
 
-    def get_metadata_data(self, FilePath, data):
-        query = f"select {data} from metadata where FilePath='{FilePath}'"
+    def get_metadata_data(self, file_path, data):
+        query = f"select {data} from metadata where FilePath='{file_path}'"
         return self._run(query)
 
-    def match_location(self, Latitude, Longitude):
-        query = f"""select 1 from location where Latitude='{Latitude}'
-                and Longitude='{Longitude}'"""
+    def match_location(self, latitude, longitude):
+        query = f"""select 1 from location where Latitude='{latitude}'
+                and Longitude='{longitude}'"""
         return self._run(query)
 
-    def get_location_data(self, LocationId, data):
-        query = f"select '{data}' from location where ROWID='{LocationId}'"
+    def get_location_data(self, location_id, data):
+        query = f"select '{data}' from location where ROWID='{location_id}'"
         return self._run(query)
 
-    def get_location(self, Latitude, Longitude, column):
-        query = f"""select {column} from location where Latitude='{Latitude}'
-        and Longitude='{Longitude}'"""
+    def get_location(self, latitude, longitude, column):
+        query = f"""select {column} from location where Latitude='{latitude}'
+        and Longitude='{longitude}'"""
         return self._run(query)
 
     def _get_table(self, table):
@@ -283,4 +283,15 @@ class Sqlite:
         self.cur.execute(sql)
         self.con.commit()
 
+    def len(self, table):
+        sql = f'select count() from {table}'
+        return self._run(sql)
 
+    def get_rows(self, table):
+        """Cycle through rows in table
+        :params: str
+        :return: iter
+        """
+        self.cur.execute(f'select * from {table}')
+        for row in self.cur:
+            yield row
diff --git a/tests/test_collection.py b/tests/test_collection.py
index 6062990..3bc1737 100644
--- a/tests/test_collection.py
+++ b/tests/test_collection.py
@@ -26,6 +26,7 @@ class TestCollection:
     def setup_class(cls, sample_files_paths):
         cls.src_path, cls.file_paths = sample_files_paths
         cls.path_format = constants.default_path + '/' + constants.default_name
+        cls.logger = log.get_logger(True, True)
 
     def teardown_class(self):
         terminate_exiftool()
@@ -113,7 +114,8 @@ class TestCollection:
                             assert part == '', file_path
 
     def test_sort_files(self, tmp_path):
-        collection = Collection(tmp_path, self.path_format, album_from_folder=True)
+        collection = Collection(tmp_path, self.path_format,
+                album_from_folder=True, logger=self.logger)
         loc = GeoLocation()
         summary, result = collection.sort_files([self.src_path], loc)
 
@@ -121,6 +123,10 @@ class TestCollection:
         assert summary, summary
         assert result, result
 
+        summary, result = collection.check_files()
+        assert summary, summary
+        assert result, result
+
         for file_path in tmp_path.glob('**/*'):
             if '.db' not in str(file_path):
                 media = Media(file_path, tmp_path, album_from_folder=True)
@@ -130,12 +136,21 @@ class TestCollection:
 
         # test with populated dest dir
         randomize_files(tmp_path)
+        summary, result = collection.check_files()
+        assert summary, summary
+        assert not result, result
+
+        collection = Collection(tmp_path, None, mode='move', logger=self.logger)
+        summary = collection.update(loc)
+        assert summary, summary
+
         collection = Collection(tmp_path, self.path_format, album_from_folder=True)
         loc = GeoLocation()
         summary, result = collection.sort_files([self.src_path], loc)
 
         assert summary, summary
         assert result, result
+
         # TODO check if path follow path_format
 
     def test_sort_files_invalid_db(self, tmp_path):
@@ -183,8 +198,9 @@ class TestCollection:
     def test_sort_similar_images(self, tmp_path):
         path = tmp_path / 'collection'
         shutil.copytree(self.src_path, path)
-        logger = log.get_logger(True, True)
-        collection = Collection(path, None, mode='move', logger=logger)
+        collection = Collection(path, None, mode='move', logger=self.logger)
+        loc = GeoLocation()
+        summary = collection.init(loc)
         summary, result = collection.sort_similar_images(path, similarity=60)
 
         # Summary is created and there is no errors