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How do I perform the SQL Join equivalent in MongoDB?
...se Mongo is not a relational database, and the devs are being careful to recommend specific use cases for $lookup, but at least as of 3.2 doing join is now possible with MongoDB.
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How to log cron jobs?
...so you can see cron related entries by using:
grep CRON /var/log/syslog
https://askubuntu.com/questions/56683/where-is-the-cron-crontab-log
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How to check if a query string value is present via JavaScript?
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Floating point vs integer calculations on modern hardware
... 6.342832
double mul: 6.321899
double div: 15.362536
This uses code from http://pastebin.com/Kx8WGUfg as benchmark-pc.c
g++ -fpermissive -O3 -o benchmark-pc benchmark-pc.c
I've run multiple passes, but this seems to be the case that general numbers are the same.
One notable exception seems to ...
What is a NullPointerException, and how do I fix it?
... the object you get a NullPointerException. In the most trivial cases, the compiler will catch the problem and let you know that "num may not have been initialized," but sometimes you may write code that does not directly create the object.
For instance, you may have a method as follows:
public void...
Should I use single or double colon notation for pseudo-elements?
...r, even though the rest of the selector may look reasonable in CSS 2.1.
http://www.w3.org/TR/CSS2/syndata.html#rule-sets
You could however use
.foo:after { /*styles*/ }
.foo::after { /*styles*/ }
On the other hand this is more verbose than necessary; for now, you can stick with the one-colon ...
How to change the value of attribute in appSettings section with Web.config transformation
...eUploader: {
brandingHtml: "Powered by \u003ca href=\"https://imgur.com/\"\u003e\u003csvg class=\"svg-icon\" width=\"50\" height=\"18\" viewBox=\"0 0 50 18\" fill=\"none\" xmlns=\"http://www.w3.org/2000/svg\"\u003e\u003cpath d=\"M46.1709 9.17788C46.1709 8.26454 46.2665 7.94324 4...
Making interface implementations async
...eUploader: {
brandingHtml: "Powered by \u003ca href=\"https://imgur.com/\"\u003e\u003csvg class=\"svg-icon\" width=\"50\" height=\"18\" viewBox=\"0 0 50 18\" fill=\"none\" xmlns=\"http://www.w3.org/2000/svg\"\u003e\u003cpath d=\"M46.1709 9.17788C46.1709 8.26454 46.2665 7.94324 4...
What is the difference between “INNER JOIN” and “OUTER JOIN”?
...
Assuming you're joining on columns with no duplicates, which is a very common case:
An inner join of A and B gives the result of A intersect B, i.e. the inner part of a Venn diagram intersection.
An outer join of A and B gives the results of A union B, i.e. the outer parts of a Venn diagram un...
How to properly import a selfsigned certificate into Java keystore that is available to all Java app
...ady using it like this:
$ echo -n | openssl s_client -connect www.example.com:443 | \
sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > /tmp/examplecert.crt
Optionally verify the certificate information:
$ openssl x509 -in /tmp/examplecert.crt -text
Import the certificate into the J...