Tutorial by Examples: et

Predicates that reason about instantiations are called meta-logical. Examples are: var/1 ground/1 integer/1 These predicates are outside the realm of pure monotonic logic programs, because they break properties like commutativity of conjunction. Other predicates that are meta-logical includ...

In oracle, the difference (in days and/or fractions thereof) between two DATEs can be found using subtraction: SELECT DATE '2016-03-23' - DATE '2015-12-25' AS difference FROM DUAL; Outputs the number of days between the two dates: DIFFERENCE ---------- 89 And: SELECT TO_DATE( '201...

The MEDIAN function since Oracle 10g is an easy to use aggregation function: SELECT MEDIAN(SAL) FROM EMP It returns the median of the values Works on DATETIME values too. The result of MEDIAN is computed by first ordering the rows. Using N as the number of rows in the group, Oracle calcula...

Pyinstaller is a normal python package. It can be installed using pip: pip install pyinstaller Installation in Windows For Windows, pywin32 or pypiwin32 is a prerequisite. The latter is installed automatically when pyinstaller is installed using pip. Installation in Mac OS X PyInstaller works...

The datetime module can convert a POSIX timestamp to a ITC datetime object. The Epoch is January 1st, 1970 midnight. import time from datetime import datetime seconds_since_epoch=time.time() #1469182681.709 utc_date=datetime.utcfromtimestamp(seconds_since_epoch) #datetime.datetime(2016, 7, 2...

Angular 2.0.0-rc.4 In this example we'll create a "Hello World!" app with only one root component (AppComponent) for the sake of simplicity. Prerequisites: Node.js v5 or later npm v3 or later Note: You can check versions by running node -v and npm -v in the console/terminal. ...

For each environment you need to create a separate appsettings.{EnvironmentName}.json files: appsettings.Development.json appsettings.Staging.json appsettings.Production.json Then open project.json file and include them into "include" in "publishOptions" section. This lis...

This command will display all the registered Valet links you have created and their corresponding file paths on your computer. Command: valet links Sample Output: ... site1 -> /path/to/site/one site2 -> /path/to/site/two ... Note 1: You can run this command from anywhere not just f...

Detailed instructions on getting model-view-controller set up or installed.

Bash indirection permits to get the value of a variable whose name is contained in another variable. Variables example: $ red="the color red" $ green="the color green" $ color=red $ echo "${!color}" the color red $ color=green $ echo "${!color}" the ...

The semantics for this are similar to that of default value substitution, but instead of substituting a default value, it errors out with the provided error message. The forms are ${VARNAME?ERRMSG} and ${VARNAME:?ERRMSG}. The form with : will error our if the variable is unset or empty, whereas the ...

Shortest match: $ a='I am a string' $ echo "${a#*a}" m a string Longest match: $ echo "${a##*a}" string

Shortest match: $ a='I am a string' $ echo "${a%a*}" I am Longest match: $ echo "${a%%a*}" I

In [15]: df = pd.DataFrame({"A":[1,1,2,3,1,1],"B":[5,4,3,4,6,7]}) In [21]: df Out[21]: A B 0 1 5 1 1 4 2 2 3 3 3 4 4 1 6 5 1 7 To get unique values in column A and B. In [22]: df["A"].unique() Out[22]: array([1, 2, 3]) In [23]: df[&qu...

You can use the .Net Math class to do calculations ([System.Math]) If you want to know which methods are available you can use: [System.Math] | Get-Member -Static -MemberType Methods Here are some examples how to use the Math class: PS C:\> [System.Math]::Floor(9.42) 9 PS C:\> [System....

Hibernate can use two types of fetch when you are mapping the relationship between two entities: EAGER and LAZY. In general, the EAGER fetch type is not a good idea, because it tells JPA to always fetch the data, even when this data is not necessary. Per example, if you have a Person entity and th...

$ man -w find /usr/share/man/man1/find.1.gz $ man -w printf /usr/share/man/man1/printf.1.gz $ man -w man /usr/share/man/man1/man.1.gz

The most common way to test Angular 2 apps is with the Jasmine test framework. Jasmine allows you to test your code in the browser. Install To get started, all you need is the jasmine-core package (not jasmine). npm install jasmine-core --save-dev --save-exact Verify To verify that Jasmine is...

$(window).load() was deprecated in jQuery version 1.8 (and completely removed from jQuery 3.0) and as such should not be used anymore. The reasons for the deprecation are noted on the jQuery page about this event Caveats of the load event when used with images A common challenge developers attem...

Attach an Event Handler Since version 1.7 jQuery has the event API .on(). This way any standard javascript event or custom event can be bound on the currently selected jQuery element. There are shortcuts such as .click(), but .on() gives you more options. HTML <button id="foo">b...