Tutorial by Examples: ar

Sometimes we want to use a where query on a a collection of records returned which is not ActiveRecord::Relation.Hence we get the above error as Where clause is know to ActiveRecord and not to Array. There is a precise solution for this by using Joins. EXAMPLE:- Suppose i need to find all user ...

public static Boolean ExportDB(String DATABASE_NAME , String packageName , String folderName){ //DATABASE_NAME including ".db" at the end like "mayApp.db" String DBName = DATABASE_NAME.substring(0, DATABASE_NAME.length() - 3); File data = Environment.getDataDir...

Although it might not be proper to do such thing in a view if you intend to separate concerns strictly, the php Blade directive allows a way to execute PHP code, for instance, to set a variable: @php($varName = 'Enter content ') (same as:) @php $varName = 'Enter content '; @endphp late...

Processing provides method rect() to draw a rectangle. This code draws a white 50 X 50 rectangle on black background. void setup() { size(500, 500); background(0); fill(255); noStroke(); } void draw() { rect(225, 225, 50, 50); } The signature of method rect() is thi...

In this example, we will look at a method for returning the last non-empty column in a row. This method will work regardless of empty regions within the data set. However caution should be used if merged cells are involved, as the End method will be "stopped" against a merged region, ret...

If you're creating an image, decoding an image, or resizing an image to fit the large notification image area, you can get the correct pixel dimensions like so: Resources resources = context.getResources(); int width = resources.getDimensionPixelSize(android.R.dimen.notification_large_icon_width)...

select :start_value + level -1 n from dual connect by level <= :end_value - :start_value + 1

PERFORM VARYING TALLY FROM 1 BY 1 UNTIL TALLY > 5 DISPLAY TALLY END-PERFORM

This is a contrived sample. It sorts records based on an ALPHABET that has upper and lower case characters together, with A and a swapped compared to the other letters. This was done on purpose to demonstrate the possibilities. The SORT algorithm reader retrieves records using RELEASE in the INPU...

This is a seedwork sample. The SORT OUTPUT PROCEDURE could manipulate the sorted records before they are returned to the write portion of the internal COBOL sort algorithm. In this case, no transformation is done, work-rec is directly moved to out-rec. GCobol >>SOURCE FORMAT IS FIXED ...

You may want to read a DataFrame from a CSV (Comma separated values) file or maybe even from a TSV or WSV (tabs and whitespace separated files). If your file has the right extension, you can use the readtable function to read in the dataframe: readtable("dataset.CSV") But what if your ...

Data sets often contain comments that explain the data format or contain the license and usage terms. You usually want to ignore these lines when you read in the DataFrame. The readtable function assumes that comment lines begin with the '#' character. However, your file may use comment marks like ...

Assuming you have a model that looks like the following, we will get up an running with a simple barebones read-only API driven by Django REST Framework ("DRF"). models.py class FeedItem(models.Model): title = models.CharField(max_length=100, blank=True) url = models.URLField(b...

To separate API logic from the component, we are creating the API client as a separate class. This example class makes a request to Wikipedia API to get random wiki articles. import { Http, Response } from '@angular/http'; import { Injectable } from '@angular/core'; import { Observabl...

$url1 = [uri]::EscapeDataString("http://test.com?test=my value") # url1: http%3A%2F%2Ftest.com%3Ftest%3Dmy%20value $url2 = [uri]::EscapeUriString("http://test.com?test=my value") # url2: http://test.com?test=my%20value # HttpUtility requires at least .NET 1.1 to be instal...

Note: these examples use the variables created in the Quick Start: Encoding section above. # url1: http%3A%2F%2Ftest.com%3Ftest%3Dmy%20value [uri]::UnescapeDataString($url1) # Returns: http://test.com?test=my value # url2: http://test.com?test=my%20value [uri]::UnescapeDataString($url2) # Re...

List all the node versions installed nvm ls v4.5.0 v6.7.0 Run command using any node installed version nvm run 4.5.0 --version or nvm exec 4.5.0 node --version Running node v4.5.0 (npm v2.15.9) v4.5.0 nvm run 6.7.0 --version or nvm exec 6.7.0 node --version Running node v6.7.0...

Objective-C and Xib Add a target to an existing XCode project In the Add Target select Custom KeyBoard Add the target like this: Your project file directory should look something like this Here myKeyBoard is the name of the added Target Add new Cocoatouch file of type of type UIView and ...

roslaunch is an important tool that manages the start and stop of ROS nodes. It takes one or more "*.launch" files as arguments. For this example, I will refer to the following (as asked in this question), so how can we execute those commands consecutively & automatically : roscd ste...

Passing ByRef or ByVal indicates whether the actual value of an argument is passed to the CalledProcedure by the CallingProcedure, or whether a reference (called a pointer in some other languages) is passed to the CalledProcedure. If an argument is passed ByRef, the memory address of the argument i...