Python sqlAlchemy bulk update but non-serializable JSON attributes

Question

I am trying to better understand how I can bulk update rows in sqlAlchemy using a Python function for each row that requires dumping results to json without having to iterate over them individually:

def do_something(x):
  return x.id + x.offset

table.update({Table.updated_field: do_something(Table)})

This is a simplification of what I am trying to accomplish except I get the error TypeError: Object of type InstrumentedAttribute is not JSON serializable.

Any thoughts on how to fix the issue here?

Answer 1

Why are you casting your Table Id to a json String? remove it and try.

Edit:

You can't call the same object in bulk, you can for example:

table.update({Table.updated_field: json.dumps(object_of_my_table variable._asdict())})

If you want update your column attribute with the whole object you will must loop and dump it in the update as:

for table in dbsession.query(Table):
    table.update_field = json.dumps(table._asdict())
    dbsession.add(table).