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Selecting only numeric columns from a data frame
...traightforward, and robust to use on database-back-ended tibbles:
dplyr::select_if(x, is.numeric)
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Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?
...k around it from within psql by executing the DDL statement conditionally:
SELECT 'CREATE DATABASE mydb'
WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'mydb')\gexec
The manual:
\gexec
Sends the current query buffer to the server, then treats each column of each row of the query's outpu...
How do I select an element with its name attribute in jQuery? [duplicate]
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$('[name="ElementNameHere"]').doStuff();
jQuery supports CSS3 style selectors, plus some more.
See more
jQuery - Selectors
jQuery - [attribute=""] selector
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Select last N rows from MySQL
I want to select last 50 rows from MySQL database within column named id which is primary key . Goal is that the rows should be sorted by id in ASC order, that’s why this query isn’t working
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How to count occurrences of a column value efficiently in SQL?
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This should work:
SELECT age, count(age)
FROM Students
GROUP by age
If you need the id as well you could include the above as a sub query like so:
SELECT S.id, S.age, C.cnt
FROM Students S
INNER JOIN (SELECT age, count(age) a...
Insert text with single quotes in PostgreSQL
...token1$escape ' with ''$token1$ is nested$token2$
Pay attention if the $ character should have special meaning in your client software. You may have to escape it in addition. This is not the case with standard PostgreSQL clients like psql or pgAdmin.
That is all very useful for writing plpgsql fu...
minimum double value in C/C++
...tion just has to work around it. See the floating-point model in 5.2.4.2.2 Characteristics of floating types <float.h> p2 of C99 (may have been moved elsewhere since then).
– user743382
Nov 10 '14 at 22:23
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How to zero pad a sequence of integers in bash so that all have the same width?
...e small correction: strictly speaking, seq supports a subset of the format chars. that printf supports (and that subsets includes g, but not d). The behavior of characters d and g differs subtly in that d interprets 0-prefixed numbers strings as octal numbers and converts them to decimal, whereas g ...
Counting the number of option tags in a select tag in jQuery
How do I count the number of <option> s in a <select> DOM element using jQuery?
8 Answers
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How can I change IIS Express port for a site
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In Solution Explorer, right-click the name of the application and then select Properties.
Click the Web tab.
In the Servers section, under Use Local IIS Web server, in the Project URL box change the port number.
To the right of the Project URL box, click Create Virtual Directory, and then ...