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PL SQL Query to list the months between two dates

SELECT TO_CHAR(ADD_MONTHS(TRUNC(TO_DATE('01-JAN-22','DD-MON-YY'), 'MM'), LEVEL -1),'MON-YY')
MONTH_YEAR 
FROM DUAL
CONNECT BY LEVEL <= MONTHS_BETWEEN(TO_DATE('01-DEC-22','DD-MON-YY'), 
    TO_DATE('01-JAN -22','DD-MON-YY')) + 1
ORDER BY LEVEL;

Result set

MONTH_YEAR
JAN-22
FEB-22
MAR-22
APR-22
MAY-22
JUN-22
JUL-22
AUG-22
SEP-22
OCT-22
NOV-22
DEC-22

Middleware functions are functions that have access to the request object (req), the response object (res), and the next function in the application’s request-response cycle. The next function is a function in the Express router which, when invoked, executes the middleware succeeding the current middleware.

Middleware functions can perform the following tasks:

• Execute any code.
• Make changes to the request and the response objects.
• End the request-response cycle.
• Call the next middleware in the stack.

If the current middleware function does not end the request-response cycle, it must call next() to pass control to the next middleware function. Otherwise, the request will be left hanging.

To load the middleware function, call app.use(), specifying the middleware function.

For example, the following code loads the myLogger middleware function before the route to the root path (/).

const express = require('express')
const app = express()

const myLogger = function (req, res, next) {
  console.log('LOGGED')
  next()
}

app.use(myLogger)

app.get('/', (req, res) => {
res.send('Hello World!')
})

app.listen(3000)

Snippet for creating a progress bar in the header section.

  <div class="header mt-100">
    <div class="row">
      <div class="progress">
        <div class="progress-bar" id="myBar"></div>
      </div>
    </div>
  </div>

  <script>
    // When the user scrolls the page, execute scrollFn 
    window.onscroll = function () { scrollFn() };

    function scrollFn() {
      var winScroll = document.body.scrollTop || document.documentElement.scrollTop;
      var height = document.documentElement.scrollHeight - document.documentElement.clientHeight;
      var scrolled = (winScroll / height) * 100;
      document.getElementById("myBar").style.width = scrolled + "%";
    }
  </script>

What is a port?

A port is a virtual point where network connections starts and end. Ports are software based and managed by a computer’s operating system. Each port is associated with a specific process or service. Ports allow computers to easily differentiate between different kinds of traffic: emails go to a different port than webpages, for instance, even though both reach a computer over the same Internet connection.

What is a port number?

Ports are standardized across all network-connected devices, with each port assigned a number. Most ports are reserved for certain protocols — for example, all Hypertext Transfer Protocol (HTTP) messages go to port 80. While IP addresses enable messages to go to and from specific devices, port numbers allow targeting of specific services or applications within those devices.

References

Cloudflare

A database management system (DBMS) is software that controls the storage, organization, and retrieval of data.

Typically, a DBMS has the following elements:

• Kernel code
  This code manages memory and storage for the DBMS.

• Repository of metadata
  This repository is usually called a data dictionary.

• Query language
  This language enables applications to access the data.

A database application is a software program that interacts with a database to access and manipulate data.

The first generation of database management systems included the following types:

• Hierarchical
  A hierarchical database organizes data in a tree structure. Each parent record has one or more child records, similar to the structure of a file system.

• Network
  A network database is similar to a hierarchical database, except records have a many-to-many rather than a one-to-many relationship.

References

Oracle

In his seminal 1970 paper “A Relational Model of Data for Large Shared Data Banks,” E. F. Codd defined a relational model based on mathematical set theory. Today, the most widely accepted database model is the relational model.

A relational database is a database that conforms to the relational model. The relational model has the following major aspects:

• Structures
  Well-defined objects store or access the data of a database.

• Operations
  Clearly defined actions enable applications to manipulate the data and structures of a database.

• Integrity rules
  Integrity rules govern operations on the data and structures of a database.

A relational database stores data in a set of simple relations. A relation is a set of tuples (rows). A tuple is an unordered set of attribute (columns) values.

A table is a two-dimensional representation of a relation in the form of rows (tuples) and columns (attributes). Each row in a table has the same set of columns. A relational database is a database that stores data in relations (tables). For example, a relational database could store information about company employees in an employee table, a department table, and a salary table.

References

Oracle