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How do I create test and train samples from one dataframe with pandas?
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PostgreSQL return result set as JSON array?
...e result looks like this:
[{"a":1,"b":"value1"},{"a":2,"b":"value2"},{"a":3,"b":"value3"}]
9.3 and up
The json_agg function produces this result out of the box. It automatically figures out how to convert its input into JSON and aggregates it into an array.
SELECT json_agg(t) FROM t
There is ...
Overload constructor for Scala's Case Classes?
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retronymretronym
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How to get the name of a function in Go?
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answered Aug 13 '11 at 23:10
moraesmoraes
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Create a custom event in Java
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edited Jun 3 '17 at 15:58
Joel eldo
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answered Jun 7 '11 at 18:50
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Ruby on Rails: How do I add a not null constraint to an existing column using a migration?
In my Rails (3.2) app, I have a bunch of tables in my database but I forgot to add a few not null constraints. I've googled around but I can't find how to write a migration which adds not null to an existing column.
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What's quicker and better to determine if an array key exists in PHP?
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edited Mar 11 '15 at 23:07
alex
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answe...
How to use a WSDL file to create a WCF service (not make a call)
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answered Jun 4 '09 at 13:29
marc_smarc_s
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How to empty a list in C#?
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237
It's really easy:
myList.Clear();
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Byte order mark screws up file reading in Java
...at its beginning, as defined by
* <a href="http://www.faqs.org/rfcs/rfc3629.html">RFC 3629 - UTF-8, a transformation format of ISO 10646</a>
*
* <p>The
* <a href="http://www.unicode.org/unicode/faq/utf_bom.html">Unicode FAQ</a>
* defines 5 types of BOMs:<ul>...