How to set up and use the Loading plugin?

[cmmercer]

I have enabled the Loading plugin, and successfully opened the GUI to edit sample loads. However, when I try to add a load, I get an error about the LoadPositionTbl (see stack trace below); I'm guessing I don't have things set up correctly in the DB. I did drop a txt file with the tray positions in data/.dvc/MetaData/load_holders/, but that may be unrelated. Any guidance on proper setup would be great!

  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\engine\base.py", line 1278, in _execute_context
    cursor, statement, parameters, context
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\engine\default.py", line 593, in do_execute
    cursor.execute(statement, parameters)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\cursors.py", line 148, in execute
    result = self._query(query)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\cursors.py", line 310, in _query
    conn.query(q)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\connections.py", line 548, in query
    self._affected_rows = self._read_query_result(unbuffered=unbuffered)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\connections.py", line 775, in _read_query_result
    result.read()
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\connections.py", line 1156, in read
    first_packet = self.connection._read_packet()
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\connections.py", line 725, in _read_packet
    packet.raise_for_error()
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\protocol.py", line 221, in raise_for_error
    err.raise_mysql_exception(self._data)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\err.py", line 143, in raise_mysql_exception
    raise errorclass(errno, errval)
pymysql.err.OperationalError: (1054, "Unknown column 'LoadPositionTbl.nxtals' in 'field list'")

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\traits\trait_notifiers.py", line 342, in __call__
    self.handler(*args)
  File "C:\Users\IGSKACCG-DAGL\Documents\Argon_Lab\Pychron\Pychron\pychron\loading\loading_manager.py", line 838, in _selected_instances_changed
    self.load_load_by_name()
  File "C:\Users\IGSKACCG-DAGL\Documents\Argon_Lab\Pychron\Pychron\pychron\loading\loading_manager.py", line 307, in load_load_by_name
    for ln, poss in groupby_key(loadtable.loaded_positions, "identifier"):
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\orm\attributes.py", line 287, in __get__
    return self.impl.get(instance_state(instance), dict_)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\orm\attributes.py", line 723, in get
    value = self.callable_(state, passive)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\orm\strategies.py", line 760, in _load_for_state
    session, state, primary_key_identity, passive
  File "<string>", line 1, in <lambda>
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\orm\strategies.py", line 902, in _emit_lazyload
    .with_post_criteria(set_default_params)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\ext\baked.py", line 545, in all
    return list(self)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\ext\baked.py", line 445, in __iter__
    return q._execute_and_instances(context)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\orm\query.py", line 3528, in _execute_and_instances
    result = conn.execute(querycontext.statement, self._params)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\engine\base.py", line 1014, in execute
    return meth(self, multiparams, params)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\sql\elements.py", line 298, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\engine\base.py", line 1133, in _execute_clauseelement
    distilled_params,
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\engine\base.py", line 1318, in _execute_context
    e, statement, parameters, cursor, context
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\engine\base.py", line 1512, in _handle_dbapi_exception
    sqlalchemy_exception, with_traceback=exc_info[2], from_=e
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\util\compat.py", line 178, in raise_
    raise exception
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\engine\base.py", line 1278, in _execute_context
    cursor, statement, parameters, context
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\sqlalchemy\engine\default.py", line 593, in do_execute
    cursor.execute(statement, parameters)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\cursors.py", line 148, in execute
    result = self._query(query)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\cursors.py", line 310, in _query
    conn.query(q)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\connections.py", line 548, in query
    self._affected_rows = self._read_query_result(unbuffered=unbuffered)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\connections.py", line 775, in _read_query_result
    result.read()
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\connections.py", line 1156, in read
    first_packet = self.connection._read_packet()
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\connections.py", line 725, in _read_packet
    packet.raise_for_error()
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\protocol.py", line 221, in raise_for_error
    err.raise_mysql_exception(self._data)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\pymysql\err.py", line 143, in raise_mysql_exception
    raise errorclass(errno, errval)
sqlalchemy.exc.OperationalError: (pymysql.err.OperationalError) (1054, "Unknown column 'LoadPositionTbl.nxtals' in 'field list'")
[SQL: SELECT `LoadPositionTbl`.id AS `LoadPositionTbl_id`, `LoadPositionTbl`.identifier AS `LoadPositionTbl_identifier`, `LoadPositionTbl`.position AS `LoadPositionTbl_position`, `LoadPositionTbl`.`loadName` AS `LoadPositionTbl_loadName`, `LoadPositionTbl`.weight AS `LoadPositionTbl_weight`, `LoadPositionTbl`.note AS `LoadPositionTbl_note`, `LoadPositionTbl`.nxtals AS `LoadPositionTbl_nxtals` 
FROM `LoadPositionTbl` 
WHERE %(param_1)s = `LoadPositionTbl`.`loadName`]
[parameters: {'param_1': ''}]
(Background on this error at: http://sqlalche.me/e/13/e3q8)```

[cmmercer]

Looks like I needed to add another column ("nxtals", INT data type, NULL by default) to the LoadPositionTbl in the database. This seems to have fixed the issue that raised the stack trace above. However, when I try to add a load in the Loading GUI, I see a popup prompting for a name and a holder, but it is not added and I do not see the holder rendered. Am I missing something else?

[cmmercer]

I noticed the LoadHolderTbl was empty in our database. I added the name of the holder I wanted to use as a new record in the table, and then the Loading GUI was able to add a new load using that holder! Seems resolved; hope my thinking out loud helps someone...

[jirhiker]

Sounds like you resolved it.

Yea unfortunately you need both the txt file for the load holder in your MetaData repo, and the name of the load holder in LoadHolderTbl.

[jirhiker]

see https://github.com/NMGRL/pychron/wiki/Load-Tray-Maps

[cmmercer]

Okay, next question on use: I tried creating an experiment queue using the new load I had entered. I named the load for an irradiation package (DT-48) with a -01 suffix; but do load names need to only be numeric? I got the following stack trace, which says load_name must be a string but was supplied with a string (seems like that should work?):

  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\traits\trait_notifiers.py", line 342, in __call__
    self.handler(*args)
  File "C:\Users\IGSKACCG-DAGL\Documents\Argon_Lab\Pychron\Pychron\pychron\experiment\queue\factory.py", line 239, in _select_existing_load_name_button_fired
    self.load_name = lv.selected.name
  File "C:\Users\IGSKACCG-DAGL\Documents\Argon_Lab\Pychron\Pychron\pychron\core\pychron_traits.py", line 140, in validate
    self.error(obj, name, value)
  File "C:\Users\IGSKACCG-DAGL\.edm\envs\pychron\lib\site-packages\traits\base_trait_handler.py", line 75, in error
    object, name, self.full_info(object, name, value), value
traits.trait_errors.TraitError: The 'load_name' trait of an ExperimentQueueFactory instance must be a string, but a value of 'DT-48-01' <class 'str'> was specified.