Why do I receive warnings after using biblatex?

Question

First of all, I'm quite new to LaTex. I watched some tutorials but this is my first real document i want to create.

I wanted to add a bibliography to my document, so i did some googling around. But after using my only refrence that I added to the .bib file, I receiving two warnings: Please (re)run Biber on the file and There were undefined references. Why do I receive these warnings? How can I remove them?

I used MiKTeX and TexMaker on Windows. I set TexMaker up like the following:

As quick build I choosed the second option (PdfLatTeX, Bib(la)tex, PdfLaTeX (2x), View Pdf).

My main.tex file looks like this:

% Template for a Scientific Document at the iu International University of Applied Sciences
% Template created by Jan Graf <jan.graf@iu-study.org>
% Set document class to article and define basics
\documentclass[11pt,a4paper,oneside]{article}
%% Packaes and formalities
\usepackage[T1]{fontenc} % use T1 for font encoding
\usepackage[english]{babel} % set language to english
\usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry} % set margins
\usepackage{setspace} % allow configuration of line spacing
\onehalfspacing % set line spacing to 1.5
\usepackage{titlesec} % use package for style titles
\usepackage{graphicx} % package for images
\usepackage[export]{adjustbox} % package for boxing
\usepackage{titling} % package for subtitles
% Package und setup for table of contents
\addto\captionsenglish{\renewcommand{\contentsname}{Table of Contents}} % Change heading to "Table of Contents" (needs to be placed before package import)
\usepackage{tocloft} % package for styling the table of contents
% Add citation package
\usepackage{csquotes}
\usepackage[
    backend=biber,
    bibencoding=utf8,
    style=apa
]{biblatex}
\addbibresource{Sources.bib}
% Font Setup
\usepackage{fontspec} % use package for font styling
\setmainfont{Arial} % set font family to arial
\titleformat{\section}{\normalfont\fontsize{12pt}{1.5}\bfseries}{\thesection}{1em}{} % set font for headings (fontsize, linespacing, arabic numbers and horizontal space between number and text)
\titleformat{\subsection}{\normalfont\fontsize{12pt}{1.5}\bfseries}{\thesubsection}{1em}{} % set font for headings (fontsize, linespacing, arabic numbers and horizontal space between number and text)
\titleformat{\subsubsection}{\normalfont\fontsize{12pt}{1.5}\bfseries}{\thesubsubsection}{1em}{} % set font for headings (fontsize, linespacing, arabic numbers and horizontal space between number and text)
% Load package to change the layout of a single or multiple pages
\usepackage{changepage}
\setlength{\parindent}{0pt} % no indent
\setlength{\parskip}{1.5pt}{} % linespace of 1.5pt after line break
%% Basic Defintions of the document
\def \DocumentTitle {Data Visualization in Python}
\def \DocumentSubTitle {A comparison of different data visualiation libraries}
\def \DocumentType {Written Assignment}
\def \DocumentAuthor{Jan Graf}
\def \MatriculationNumber{4236721}
\def \Course{Computer Science (M.Sc.)\}
\def \CourseCode{DLMDSPW01 - Programming with Python\}
\def \Tutor{Dr. Cosmina Croitoru}
\author{\DocumentAuthor}
\title{\DocumentTitle}
\begin{document}
\include{Pages/Cover}
\include{Pages/TableOfContents}
\include{Pages/Introduction}
\include{Pages/Main Body}
\include{Pages/Conclusion}
\printbibliography
\end{document}]

The reference is inside the Introduction.tex:

\section{Introduction}
For almost every offer on the internet, you have to agree to the collection of cookies. This goes hand in hand with the storage of personal data. Every day, billions of people collect an inconceivably large amount of data. Big data is no longer a new term, but is on everyone's lips. A central reason for storing the enormous amounts of data is the information it contains. This is a commodity that has long been an integral part of modern society. Carly Fiorina, an US american politician, once said: "The goal is to turn data into information and information into insight" \autocite{Nantasenamat2020}. \\
To get the information out of data and turn it into insight the processing and visualization is an important part. Raw data needs to be processed to get the informations needed. An equally important part is the visualition to make the containend informations more accessible to humans. It is in the nature of a human brain, that graphs, charts and images are easier to understand as a huge amount of data, especially if there are correlations involved.

The Sources.bib file:

@misc{Nantasenamat2020,
  author = {Chanin Nantasenamat},
  title = {101 Data Science Qutotes},
  howpublished = {\url{https://medium.com/data-professor/101-data-science-quotes-afad20d1e6ee}},
  year = {2020}, 
  note = {[Online; Accessed 17 June.2023]},
}

The log can be found in gist.

Can anyone help to remove the warnings?

Answer 1

I guess by "compiling", you mean "running LuaLaTeX". But what you need is to also run a second external program: biber. You need to run biber each time you add or delete \cite-type commands. A full compilation run thus consists of lualatex - biber - lualatex.

Incidentally, please do replace

howpublished = {\url{https://medium.com/data-professor/101-data-science-quotes-afad20d1e6ee}},
note = {[Online; Accessed 17 June.2023]},

with

url  = {https://medium.com/data-professor/101-data-science-quotes-afad20d1e6ee},
note = {Online; accessed 17 June 2023},

and be sure to load the xurl package, which allows line breaking of URL strings at all points in the string.

\documentclass[11pt,a4paper,oneside]{article}
\begin{filecontents}[overwrite]{Sources.bib}
@misc{Nantasenamat2020,
  author = {Chanin Nantasenamat},
  title  = {101 Data Science Quotes},
  year   = {2020}, 
  url    = {https://medium.com/data-professor/101-data-science-quotes-afad20d1e6ee},
  note   = {Online; accessed 17 June 2023},
}
\end{filecontents}
%% Packages and formalities
%%%\usepackage[T1]{fontenc} % not useful with LuaLaTeX
\usepackage[english]{babel} % set language to US English
\addto\captionsenglish{\renewcommand{\contentsname}{Table of Contents}}
\usepackage[margin=2cm]{geometry} % set margins
\usepackage{setspace} % line spacing options
\onehalfspacing % set line spacing to 1.5
\usepackage{graphicx} % package for images
\usepackage[export]{adjustbox} % package for boxing
\usepackage{titling} % package for subtitles
\usepackage{tocloft} % package for styling the table of contents
\usepackage{csquotes} % define \enquote macro
% Citation management package
\usepackage[
    backend=biber,
    bibencoding=utf8,
    style=apa
]{biblatex}
\addbibresource{Sources.bib}
% Font Setup
\usepackage{fontspec} % package for font styling
\setmainfont{Arial}   % set font family to arial
\usepackage{titlesec} % package to modify titles
\titleformat{\section}{\normalfont\fontsize{12pt}{1.5}\bfseries}{\thesection}{1em}{}
% Load package to change the layout of a single or multiple pages
\usepackage{changepage}
\setlength{\parindent}{0pt} % no indent
\setlength{\parskip}{1.5pt}{} % linespace of 1.5pt after line break
%% Basic Definitions of the document
\def \DocumentTitle {Data Visualization in Python}
\def \DocumentSubTitle {A comparison of different data visualiation libraries}
\def \DocumentType {Written Assignment}
\def \DocumentAuthor{Jan Graf}
\def \MatriculationNumber{4236721}
\def \Course{Computer Science (M.Sc.)\}
\def \CourseCode{DLMDSPW01 -- Programming with Python\}
\def \Tutor{Dr.\ Cosmina Croitoru}
\author{\DocumentAuthor}
\title{\DocumentTitle} 
\date{}
% new:
\usepackage{xurl} % allow line breaks at all points in a URL string
\begin{document}
\maketitle
\section{Introduction}
For almost every \dots\ \autocite{Nantasenamat2020}.
\printbibliography
\end{document}