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Why are ToLookup and GroupBy different?
...happens when you call ToLookup on an object representing a remote database table with a billion rows in it?
The billion rows are sent over the wire, and you build the lookup table locally.
What happens when you call GroupBy on such an object?
A query object is built; end of story.
When that quer...
Switch on Enum in Java [duplicate]
...r speed, the switch statement approach might be faster because it's just a table lookup in the bytecode. With your approach, you have to push a new function onto the stack. It's a micro-optimization, but if speed is super important it's something to keep in mind.
– DIMMSum
...
How to change the style of alert box?
...
the custom alert in the answer is not compatable to the native alert. The native alert and prompt are block-and-wait.
– Beeno Tung
Jun 17 '19 at 8:32
...
Defining a HTML template to append using JQuery
...en-template').html();
$('button.addRow').click(function() {
$('#targetTable').append(template);
});
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Scheduling R Script
..., to run scheduler first install below packages
install.packages('data.table')
install.packages('knitr')
install.packages('miniUI')
install.packages('shiny')
install.packages("taskscheduleR", repos = "http://www.datatailor.be/rcube", type =
"source")
After installing go to
**TOOLS...
How to get UTF-8 working in Java webapps?
...ding=true&characterEncoding=UTF-8"
/>
MySQL database and tables
The used database must use UTF-8 encoding. This is achieved by creating the database with the following:
CREATE DATABASE `ID_development`
/*!40100 DEFAULT CHARACTER SET utf8 COLLATE utf8_swedish_ci */;
Then,...
Explanation of JSONB introduced by PostgreSQL
...me operation at a json typed value)
When jsonb will be available with a stable release, there will be two major use cases, when you can easily select between them:
If you only work with the JSON representation in your application, PostgreSQL is only used to store & retrieve this representati...
Parsing JSON using Json.net
...rays and Objects. These correspond here to the datatypes ArrayList and Hashtable.
/// All numbers are parsed to doubles.
/// </summary>
using System;
using System.Collections;
using System.Globalization;
using System.Text;
public class JSON
{
public const int TOKEN_NONE = ...
Why does calling a method in my derived class call the base class method?
...
You can imagine, that a class, when instantiated, is nothing more than a table of pointers, pointing to the actual implementation of its methods. The following image should visualize this pretty well:
Now there are different ways, a method can be defined. Each behaves different when it is used ...
Which annotation should I use: @IdClass or @EmbeddedId
...ingle property, and it permits the reuse of the @Embeddable class in other tables.
The next most natural approach is the use of the @EmbeddedId tag. Here, the primary key class cannot be used in other tables since it is not an @Embeddable entity, but it does allow us to treat the key as a
single a...