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Ways to implement data versioning in MongoDB
...nt data versioning in MongoDB. (I've asked similar question regarding Cassandra . If you have any thoughts which db is better for that please share)
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Data binding to SelectedItem in a WPF Treeview
...selects an item (aka OneWayToSource)?
– Shimmy Weitzhandler
Nov 21 '17 at 21:23
add a comment
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How do I clone a Django model instance object and save it to the database?
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Just change the primary key of your object and run save().
obj = Foo.objects.get(pk=<some_existing_pk>)
obj.pk = None
obj.save()
If you want auto-generated key, set the new key to None.
More on UPDATE/INSERT here.
Official docs on copying model instances: h...
Can I install Python windows packages into virtualenvs?
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@CodyHatch You can as this is not my only answer on SO and there's a chance some of my other answers would be helpful to you as well :)
– Piotr Dobrogost
Nov 26 '13 at 16:43
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Python: reload component Y imported with 'from X import Y'?
...nce I have imported a module X in an interpreter session using import X , and the module changes on the outside, I can reload the module with reload(X) . The changes then become available in my interpreter session.
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Python list directory, subdirectory, and files
I'm trying to make a script to list all directory, subdirectory, and files in a given directory.
I tried this:
7 Answers
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Is the C# static constructor thread safe?
.... https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/static-constructors
The implementation shown is thread safe for the initial construction, that is, no locking or null testing is required for constructing the Singleton object. However, this does not mean that an...
Getting a map() to return a list in Python 3.x
I'm trying to map a list into hex, and then use the list elsewhere. In python 2.6, this was easy:
9 Answers
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Best way to do multi-row insert in Oracle?
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In Oracle, to insert multiple rows into table t with columns col1, col2 and col3 you can use the following syntax:
INSERT ALL
INTO t (col1, col2, col3) VALUES ('val1_1', 'val1_2', 'val1_3')
INTO t (col1, col2, col3) VALUES ('val2_1', 'val2_2', 'val2_3')
INTO t (col1, col2, col3) VALUES ...
Paste multiple columns together
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no need for apply here; paste is vectorised, and that's more efficient
– baptiste
Jan 28 '13 at 21:49
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