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mongodb count num of distinct values per field/key
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MongoDB has a distinct command which returns an array of distinct values for a field; you can check the length of the array for a count.
There is a shell db.collection.distinct() helper as well:
> db.countries.distinct('country');
[ "Spain", "...
throw checked Exceptions from mocks with Mockito
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extra: Mocktio will not complain if you doThrow an a method without any throwables, but you will also get this exception
– dwana
Sep 25 '15 at 7:36
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Why is '+' not understood by Python sets?
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97
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How do I choose between Semaphore and SemaphoreSlim?
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Maven: Command to update repository after adding dependency to POM
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mvn install (or mvn package) will always work.
You can use mvn compile to download compile time dependencies or mvn test for compile time and test dependencies but I prefer something that always works.
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Get value from JToken that may not exist (best practices)
...eneric method Value() is for. You get exactly the behavior you want if you combine it with nullable value types and the ?? operator:
width = jToken.Value<double?>("width") ?? 100;
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Change a column type from Date to DateTime during ROR migration
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How to completely remove borders from HTML table
...e so far (don't work with tables that often). It makes some tasks bit more complicated. E.g. when you want to include two different borders in same place (visually), while one being TOP for one row, and second being BOTTOM for other row. They will collapse (= only one of them will be shown). Then yo...
String.IsNullOrWhiteSpace in LINQ Expression
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Why? This code compiles: List<string> my = new List<string>(); var i = from m in my where !string.IsNullOrWhiteSpace(m) select m;
– Eric J.
Mar 7 '12 at 18:24
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