Add a dont_fetch query parameter

[danbolinson]

The new fetch_only argument to searches is wonderful! Can we also get its inverse?

Most of the time I use fetch_only, what I really want is to EXCLUDE a column, vs selecting the columns I want.

I can do something like:

dont_fetch = ['some_column']
columns = [c['name'] for c in my_table.list_columns() if c['name'] not in dont_fetch]
my_results = my_tables.search(q.fetch_only(*columns))

But I’d like to be able to just do:

dont_fetch = ['some_column']
my_results = my_tables.search(q.dont_fetch(*dont_fetch))

[ianb]

+1 For the feature request.

This did come up before, but if it was a feature using the code would be less clunky that the solution we came up with.

[ianb]

Accelerated Tables for Everyone DELAYED to late April/early May

@jshaffstall you just reminded me we already went over this with a question @rickhurlbatt asked when the beta came out, also we had built some code for “all columns except explicitly specified ones to leave out” we came up with:

@p.colbert

def q_fetch_none_of(table, column_names_to_exclude):
  table = (
    getattr(app_tables, table)  if isinstance(table, str)
    else  table
  )
  return q.fetch_only(*[
    c['name']
    for c in table.list_columns()
    if c['name'] not in column_names_to_exclude
  ])

The ‘clunky’ part of this solution is you have to pass in the table object or name of the table to the function, but other than that, its the same as the solution you already use.