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How to get a number of random elements from an array?
...- Math.random());
// Get sub-array of first n elements after shuffled
let selected = shuffled.slice(0, n);
DEMO:
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Select by partial string from a pandas DataFrame
...ns of which 2 contain string values. I was wondering if there was a way to select rows based on a partial string match against a particular column?
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How can I set the value of a DropDownList using jQuery?
... have described above, yet the range validator keeps failing telling me to select a value (when the value selected is within range). Please see my question stackoverflow.com/questions/3165033/…
– James
Jul 7 '10 at 13:14
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Select mySQL based only on month and year
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SELECT * FROM projects WHERE YEAR(Date) = 2011 AND MONTH(Date) = 5
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When to use Common Table Expression (CTE)
...ing well? Can someone give me a simple example of limitations with regular select, derived or temp table queries to make the case of CTE? Any simple examples would be highly appreciated.
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How to check if a table exists in a given schema
... whether a table (or view) exists, and the current user has access to it?
SELECT EXISTS (
SELECT FROM information_schema.tables
WHERE table_schema = 'schema_name'
AND table_name = 'table_name'
);
The information schema is mainly useful to stay portable across major versions and...
How can you programmatically tell an HTML SELECT to drop down (for example, due to mouseover)?
How can you programmatically tell an HTML select to drop down (for example, due to mouseover)?
12 Answers
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How to count occurrences of a column value efficiently in SQL?
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This should work:
SELECT age, count(age)
FROM Students
GROUP by age
If you need the id as well you could include the above as a sub query like so:
SELECT S.id, S.age, C.cnt
FROM Students S
INNER JOIN (SELECT age, count(age) a...
Is there any difference between GROUP BY and DISTINCT
...CT and distinct by UNION cause an oracle error, but GROUP BY worked; I was selecting only 1 column from a view and not using any aggregation; I'm still baffled why it required it, but it does confirm there is some difference in the execution. As others point out, it also lets you GROUP BY columns no...
How to add MVC5 to Visual Studio 2013?
...onger has separate project types for different ASP.Net features.
You must select .NET Framework 4.5 (or higher) in order to see the ASP.NET Web Application template (For ASP.NET One).
So just select Visual C# > Web > ASP.NET Web Application, then select the MVC checkbox in the next step.
Not...