Biblatex: override title for specific bib entry exported from Citavi

Question

I want to cite a law but it has a very long title. The thing I want to achieve is displaying the short title (e.g. "BDSG") in my footnote and the long title ("Bundesdatenschutzgesetz") in my bibliography.

I'm using Citavi for organizing my sources. That's why I can't override the .bib entry manually, it will be overwritten every time I start a Citavi export.

This is a code sample:

\usepackage[backend=biber,dashed=false,style=authortitle]{biblatex}
\bibliography{BIBFILE}
\begin{document}
Lorem ipsum\cite{BDSG}
\printbibliography[heading=bibintoc]
\end{document}

Cite in text should be "BDSG" and the name of the source in my bibliography "Bundesdatenschutzgesetz [MORE INFORMATION]".

Do you have any idea on how to achieve this?

Answer 1

You want the shorttitle or shorthand field. So ideally things should be as easy as

@online{bdsg,
  title      = {Bundesdatenschutzgesetz},
  shorttitle = {BDSG},
}

If you, however, can't modify the .bib file, you can let Biber do it for you. The following adds shorttitle = {BDSG}, to the entry with the key bdsg.

\RequirePackage{filecontents}
\begin{filecontents*}{\jobname.bib}
@online{bdsg,
  title = {Bundesdatenschutzgesetz},
}
\end{filecontents*}


\documentclass[ngerman]{article}
\usepackage{babel}
\usepackage{csquotes}
\usepackage[backend=biber,dashed=false,style=authortitle]{biblatex}
\usepackage{hyperref}
\addbibresource{\jobname.bib}

\DeclareSourcemap{
  \maps{
    \map{
      \step[fieldsource=entrykey, match=\regexp{\A bdsg \Z}, final]
      \step[fieldset=shorttitle, fieldvalue=BDSG]
    }
  }
}

\begin{document}
\cite{bdsg}

\printbibliography
\end{document}