Tutorial by Examples: st

In order to determine some simple statistics of a value in a column of a table, you can use an aggregate function. If your individuals table is: NameAgeAllie17Amanda14Alana20 You could write this statement to get the minimum, maximum and average value: SELECT min(age), max(age), avg(age) FROM i...

In order to use Gson you have to include it in your project. You can do this by adding the following dependency of the Gson version available in Maven Central: Maven Add to pom.xml <dependencies> <dependency> <groupId>com.google.code.gson</groupId> <a...

foo = "bar" foo[0] = "c" # Error Immutable variable value can not be changed once they are created.

The maximum number of remembered commands: ~> $ echo $HISTSIZE 1000

On Debian or Ubuntu, you can install SCons using $ sudo apt-get install scons On YUM-based systems, use $ sudo yum install scons You can install using an RPM by downloading it, then running $ sudo rpm -Uvh http://prdownloads.sourceforge.net/scons/scons-2.5.0-1.noarch.rpm

On systems that use the System-V style init scripts, such as RHEL/CentOS 6: service <service> start service <service> stop On systems using systemd, such as Ubuntu (Server and Desktop) >= 15.04, and RHEL/CentOS >= 7: systemctl <service> dnsmasq systemctl <service> ...

On systems that use the System-V style init scripts, such as RHEL/CentOS 6: service <service> status On systems using systemd, such as Ubuntu (Server and Desktop) >= 15.04, and RHEL/CentOS >= 7.0: systemctl status <service>

A Connection String is a string that specifies information about a particular data source and how to go about connecting to it by storing credentials, locations, and other information. Server=myServerAddress;Database=myDataBase;User Id=myUsername;Password=myPassword; Storing Your Connection Stri...

Represents an instant in time. Can be thought of as a wrapper around a Unix timestamp. Instant now = Instant.now(); Instant epoch1 = Instant.ofEpochMilli(0); Instant epoch2 = Instant.parse("1970-01-01T00:00:00Z"); java.time.temporal.ChronoUnit.MICROS.between(epoch1, epoch2); // 0

foreach varlist1 list1 ?varlist2 list2 ...? body foreach is a powerful control structure that allows looping over a list or multiple lists. set alpha [list a b c d e f] foreach {key} $alpha { puts "key: $key" } Multiple variable names may be specified. set alphaindexes [list a ...

class base { }; class derived: public base { }; int main() { base* p = new derived(); delete p; // The is undefined behavior! } In section [expr.delete] §5.3.5/3 the standard says that if delete is called on an object whose static type does not have a virtual destructor: if the...

In C++ methods that differs only by const qualifier can be overloaded. Sometimes there may be a need of two versions of getter that return a reference to some member. Let Foo be a class, that has two methods that perform identical operations and returns a reference to an object of type Bar: class ...

This is a basic in-app keyboard. The same method could be used to make just about any keyboard layout. Here are the main things that need to be done: Create the keyboard layout in an .xib file, whose owner is a Swift or Objective-C class that is a UIView subclass. Tell the UITextField to use t...

A Static variable declared locally is not destructed and does not lose its value when the Sub procedure is exited. Subsequent calls to the procedure do not require re-initialization or assignment although you may want to 'zero' any remembered value(s). These are particularly useful when late bindin...

Streams can be built that reference themselves and thus become infinitely recursive. // factorial val fact: Stream[BigInt] = 1 #:: fact.zipWithIndex.map{case (p,x)=>p*(x+1)} fact.take(10) // (1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880) fact(24) // 620448401733239439360000 // the ...

To list files and folders inside current directory, we use ls command: user@host:/$ ls bin boot cdrom dev etc home initrd.img lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var vmlinuz ls prints folder structure in simple view, color coded by type....

requestAnimationFrame is similar to setInterval, it but has these important improvements: The animation code is synchronized with display refreshes for efficiency The clear + redraw code is scheduled, but not immediately executed. The browser will execute the clear + redraw code only when the d...

This example loads and animates and image across the Canvas Important Hint! Make sure you give your image time to fully load by using image.onload. Annotated Code <!doctype html> <html> <head> <style> body{ background-color:white; } #canvas{border:1px solid re...

If you need to clamp a number to keep it inside a specific range boundary function clamp(min, max, val) { return Math.min(Math.max(min, +val), max); } console.log(clamp(-10, 10, "4.30")); // 4.3 console.log(clamp(-10, 10, -8)); // -8 console.log(clamp(-10, 10, 12)); // ...

Detailed instructions on getting netty set up or installed.