django - What is the best way to use query with a list and keep the list order? -


this question has answer here:

i've searched online , find 1 blog seemed hackish attempt keep order of query list. hoping query using orm list of strings, doing way not keep order of list.

from understand bulk_query works if have id's of items want query.

can recommend ideal way of querying list of strings , making sure objects kept in proper order?

so in perfect world able query set of objects doing this...

entry.objects.filter(id__in=['list', 'of', 'strings'])

however, not keep order, string before list etc...

the work around see, , may tired or may acceptable i'm not sure doing this...

for in listofstrings:     object = object.objects.get(title=str(i))     myiterablecorrectorderedlist.append(object)

thank you,

the problem solution separate database query each item.

this answer gives right solution if you're using ids: use in_bulk create map between ids , items, , reorder them wish.

if you're not using ids, can create mapping yourself:

values = ['list', 'of', 'strings']  # 1 database query entries = entry.objects.filter(field__in=values)  # 1 trip through list create mapping entry_map = {entry.field: entry entry in entries}  # 1 more trip through list build ordered entries ordered_entries = [entry_map[value] value in values]

(you save line using index, in this example, since index o(n) performance not long lists.)


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