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MongoDB and “joins” [duplicate]
I'm sure MongoDB doesn't officially support "joins". What does this mean?
11 Answers
1...
How do I update an entity using spring-data-jpa?
...n plain JPA, therefore it makes your entity managed as described above. It means that calling save() on an object with predefined id will update the corresponding database record rather than insert a new one, and also explains why save() is not called create().
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Performing Inserts and Updates with Dapper
...//code.google.com/archive/p/dapper-dot-net/issues/6 for progress.
In the mean time you can do the following
val = "my value";
cnn.Execute("insert into Table(val) values (@val)", new {val});
cnn.Execute("update Table set val = @val where Id = @id", new {val, id = 1});
etcetera
See also my bl...
Why can't Python parse this JSON data?
...tionary by specifying the 'key paths'. If you get a KeyError exception it means the key doesn't exist in the path. Look out for typos or check the structure of your dictionary.
– Nuhman
May 25 '18 at 4:55
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SQL SELECT speed int vs varchar
... to link each string column to another table (relationship). however, that means more joining operations are required for each query. How do i determine if this trade-off is worth it? Thank you!
– AiRiFiEd
Mar 6 '17 at 8:45
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What is the purpose of Rank2Types?
...already support polymorphic arguments?
They do, but only of rank 1. This means that while you can write a function that takes different types of arguments without this extension, you can't write a function that uses its argument as different types in the same invocation.
For example the following...
When to use EntityManager.find() vs EntityManager.getReference() with JPA
...lly use getReference method when i do not need to access database state (I mean getter method). Just to change state (I mean setter method). As you should know, getReference returns a proxy object which uses a powerful feature called automatic dirty checking. Suppose the following
public class Pers...
Is Ruby pass by reference or by value?
...uld be pedantic and do the OP a disservice, as that isn't actually what he meant. But thanks for the clarification, because it is important for future readers and I should have included it. (I'm always torn between including more info and not confusing people.)
– Chuck
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How to join two sets in one line without using “|”
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@jorgenkg same as: set_a = set_a.union(set_b). If you mean "in-place", neither will do that, both create a new set
– nitely
Nov 10 '16 at 2:22
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Check if something is (not) in a list in Python
...000 in lst # Expected to take longer time.
68.9 ns ± 0.613 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)
178 µs ± 5.01 µs per loop (mean ± std. dev. of 7 runs, 10000 loops each)
If you want to do more than just check whether an item is in a list, there are options:
list.i...