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Group by multiple columns in dplyr, using string vector input
...r my understanding of plyr into dplyr, but I can't figure out how to group by multiple columns.
9 Answers
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How to select an option from drop down using Selenium WebDriver C#?
...ort.UI;
// select the drop down list
var education = driver.FindElement(By.Name("education"));
//create select element object
var selectElement = new SelectElement(education);
//select by value
selectElement.SelectByValue("Jr.High");
// select by text
selectElement.SelectByText("HighScho...
How do I pass a variable by reference?
The Python documentation seems unclear about whether parameters are passed by reference or value, and the following code produces the unchanged value 'Original'
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Count number of records returned by group by
How do I count the number of records returned by a group by query,
13 Answers
13
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Mysql order by specific ID values
Is it possible to sort in mysql by "order by" using predefined set of column values (ID) like: order by (ID=1,5,4,3) so I would get record 1, 5, 4, 3 in that order out?
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Ordering by the order of values in a SQL IN() clause
I am wondering if there is away (possibly a better way) to order by the order of the values in an IN() clause.
13 Answers
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How can I list all tags in my Git repository by the date they were created?
I need some way to list all tags in my system by the date they were created but am not sure if I can get that data via git-log. Ideas?
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Find most frequent value in SQL column
... COUNT(`column`) AS `value_occurrence`
FROM `my_table`
GROUP BY `column`
ORDER BY `value_occurrence` DESC
LIMIT 1;
Replace column and my_table. Increase 1 if you want to see the N most common values of the column.
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How to iterate for loop in reverse order in swift?
...unctions to iterate on ranges with a step other than one:
stride(from: to: by:), which is used with exclusive ranges and stride(from: through: by:), which is used with inclusive ranges.
To iterate on a range in reverse order, they can be used as below:
for index in stride(from: 5, to: 1, by: -1) {...
How to select unique records by SQL
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If you only need to remove duplicates then use DISTINCT. GROUP BY should be used to apply aggregate operators to each group
GROUP BY v DISTINCT
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