Fix table_description refresh (#415)

Author: jcjc712

dataherald/db_scanner/sqlalchemy.py

@@ -64,23 +64,28 @@ def refresh_tables(
         metadata: dict = None,
     ) -> list[TableDescription]:
         stored_tables = repository.find_by({"db_connection_id": str(db_connection_id)})
+        stored_tables_list = [table.table_name for table in stored_tables]
 
         rows = []
         for table_description in stored_tables:
             if table_description.table_name not in tables:
                 table_description.status = TableDescriptionStatus.DEPRECATED.value
                 rows.append(repository.save_table_info(table_description))
+            else:
+                rows.append(TableDescription(**table_description.dict()))
+
         for table in tables:
-            rows.append(
-                repository.save_table_info(
-                    TableDescription(
-                        db_connection_id=db_connection_id,
-                        table_name=table,
-                        status=TableDescriptionStatus.NOT_SCANNED.value,
-                        metadata=metadata,
+            if table not in stored_tables_list:
+                rows.append(
+                    repository.save_table_info(
+                        TableDescription(
+                            db_connection_id=db_connection_id,
+                            table_name=table,
+                            status=TableDescriptionStatus.NOT_SCANNED.value,
+                            metadata=metadata,
+                        )
                     )
                 )
-            )
         return rows
 
     @override