% This file is embedded in datatool-user.pdf version 3.4.1 2025-04-25
% Example 77 Inserting a Column at the Start of Displayed Data
% Label: "ex:displayinsertcol"
% arara: pdflatex
% arara: pdflatex
% arara: pdfcrop
\documentclass[12pt]{article}
\pagestyle{empty}
 \begin{filecontents}[noheader,overwrite]{studentmarks.csv}
Surname,Forename,StudentNo,Assign1,Assign2,Assign3
"Smith, Jr",John,102689,68,57,72
"Brown",Jane,102647,75,84,80
"Brown",Jane,102646,64,92,79
"Brown",Andy,103569,42,52,54
"Adams",Zoë,105987,52,48,57
"Brady",Roger,106872,68,60,62
"Verdon",Clare,104356,45,50,48
\end{filecontents}

\usepackage{datatool}
\DTLsetup{default-name=marks}
\DTLread{studentmarks.csv}
\ExplSyntaxOn
\RenewDocumentCommand \DTLdisplaydbAddItem 
 { m m m m m m m m }
{
 \int_compare:nNnT { #7 } = { \c_one_int }
 {
  \DTLaction[ return={ \StudentNo = StudentNo } ]
  { current ~ row ~ values }
  \tl_put_right:Nn #1 { \DTLrowincr \label }
  \tl_put_right:Nx #1 { { \StudentNo } }
  \tl_put_right:Nn #1 { \DTLtherow & }
 }
 \tl_put_right:Nn #1 { #3 { #2 } }
}
\ExplSyntaxOff 
\begin{document}
\DTLrowreset
\DTLaction[
 options={
  pre-col={r},
  pre-head={\bfseries Row &}
 }
]{display} 

\DTLaction[
 assign={
  \Surname=Surname,
  \Forename=Forename,
  \StudentNo=StudentNo
 },
 options={
  inline={% 
  \DTLifstringeq{\Surname}{Brown}
  {\DTLifstringeq{\Forename}{Andy}{#1}{}}{}% 
  }
 }
]{find}
Row \ref{\StudentNo} shows the details for Andy Brown. 
\end{document}
