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Extracting specific columns from a data frame
...r package, if your data.frame is called df1:
library(dplyr)
df1 %>%
select(A, B, E)
This can also be written without the %>% pipe as:
select(df1, A, B, E)
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Postgres: Distinct but only for one column
...h names (having more than 1 mio. rows), but I have also many duplicates. I select 3 fields: id , name , metadata .
3 Ans...
Eclipse does not highlight matching variables
...y:
window > preferences > java > editor > mark occurrences
Select all options available there.
Also go to:
Preferences > General > Editors > Text Editors > Annotations
Compare the settings for 'Occurrences' and 'Write Occurrences'
Make sure that you don't have the 'T...
How can I select all elements without a given class in jQuery?
...
You can use the .not() method or :not() selector
Code based on your example:
$("ul#list li").not(".active") // not method
$("ul#list li:not(.active)") // not selector
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Random record in ActiveRecord
...he first, all after are still sorted by id). If you need multiple randomly selected records you must use this approach multiple times or use the random order method provided by your database, i.e. Thing.order("RANDOM()").limit(100) for 100 randomly selected entries. (Be aware that it's RANDOM() in P...
What's the purpose of SQL keyword “AS”?
...ynes Yes. Just concatenate (||) the columns and then give it an alias e.g. SELECT foo || bar AS foobar.
– Rupert Madden-Abbott
Dec 10 '18 at 14:26
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How to alias a table in Laravel Eloquent queries (or using Query Builder)?
...AS. Try
$users = DB::table('really_long_table_name AS t')
->select('t.id AS uid')
->get();
Let's see it in action with an awesome tinker tool
$ php artisan tinker
[1] > Schema::create('really_long_table_name', function($table) {$table->increments('id');});
// N...
SQL - Rounding off to 2 decimal places
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Could you not cast your result as numeric(x,2)? Where x <= 38
select
round(630/60.0,2),
cast(round(630/60.0,2) as numeric(36,2))
Returns
10.500000 10.50
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contenteditable, set caret at the end of the text (cross-browser)
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function placeCaretAtEnd(el) {
el.focus();
if (typeof window.getSelection != "undefined"
&& typeof document.createRange != "undefined") {
var range = document.createRange();
range.selectNodeContents(el);
range.collapse(false);
var s...
Drop data frame columns by name
...op=FALSE to keep R from converting your data frame to a vector if you only select a single column. Don't forget that data frames are lists, so list selection (one-dimensional like I did) works perfectly well and always returns a list. Or a data frame in this case, which is why I prefer to use it.
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