Use datatool to read a row from a CSV file, then use the variables in the document?

Question

I'm confused about how to use "datatool" to read variables from a row in my database, and pass them on to be formatted in my text. I don't want to make a table, but that's about all there seems to be examples of on the Internet.

I have a CSV file made up something like this:

name|points
John|172
Sue|120
Mike|64

After two days of staring at the datatool manual, this is the extent of my success:

\documentclass{memoir}
\usepackage{datatool}
\DTLsetseparator{|}
\begin{document}
\DTLloaddb{players}{database.csv}
\DTLforeach*{players}{\name=name,\points=points}
\subsection{\name}
\textit{\points}
\end{document}

That prints the chosen variables with the formatting I desire, but it only does so with the last entry in the database. My guess is that "\dtlgetrowforvalue{players}{1}{John}" could be used to find John's row in the database, but I don't understand how to integrate that with the commands that read and display the variables.

I am unfamiliar with much of the terminology used in the manual, and finding no examples that look like what I wish to achieve, my attempts at bullying my way through by trial and error have failed. I don't necessarily need a working example, but I would very much like for someone here to put me onto the appropriate commands, at least.

Answer 1

\DTLforeach takes three compulsory arguments, not two as in your example. This fixes your example:

\documentclass{memoir}

\usepackage{datatool}
\DTLsetseparator{|}

\DTLloaddb{players}{database.csv}

\begin{document}

\DTLforeach*
{players}% database label
{\name=name,\points=points}% assignment
{% Stuff to do at each iteration:
  \subsection{\name}
  \textit{\points}
}

\end{document}

This produces:

Edit:

\DTLforeach is a repetitive (loop) command designed to perform a particular action for each row of data. If you just want to lookup information from a single row of the data, there are a number of methods to do this. Here are some examples:

\documentclass{memoir}

\usepackage{datatool}
\DTLsetseparator{|}

\DTLloaddb{players}{database.csv}

\begin{document}

Sue's points: \DTLfetch{players}{name}{Sue}{points}.

Pull information from row 3.
\DTLassign{players}{3}{\name=name,\points=points}

Here's the information: Name: \name. Points: \points.

Pull information from the first row where the name column has the
value ``John''.
\DTLassignfirstmatch{players}{name}{John}{\name=name,\points=points}

Here's the information: Name (we already know this anyway): \name.
Points: \points.

\newcommand{\PlayerName}{John}
As above, but the required name (\PlayerName) is given by a command:
\xDTLassignfirstmatch{players}{name}{\PlayerName}{\name=name,\points=points}

Here's the information: Name (we already know this anyway): \name.
Points: \points.

\end{document}

This produces:

Sue’s points: 120.
Pull information from row 3.
Here’s the information: Name: Mike. Points: 64.
Pull information from the first row where the name column has the value “John”.
Here’s the information: Name (we already know this anyway): John. Points: 172.
As above, but the required name (John) is given by a command:
Here’s the information: Name (we already know this anyway): John. Points: 172.

Answer 2

NOVEMBER 2016 SOLUTION (does not use datatool):

This solution uses my recently updated readarray package that now uses the powerful listofitems package for parsing and accessing the data.

\documentclass{article}
\usepackage{filecontents}
\begin{filecontents*}{database.csv}
name,points,d3,d4,d5,d6,d7,d8,d9,d10,d11
John,172,yes,black,23,0.000,89,big,32,A,Z
Sue,120,no,red,26,0.002,97,medium,36,B,W
Mike,64,maybe,green,89,0.567,154,small,42,C,X 
\end{filecontents*}
\usepackage{readarray}[2016-11-07]
\usepackage{ifthen}
\newcounter{recordindex}
\newcommand\findrecord[1]{%
  \def\matchrecord{0}
  \setcounter{recordindex}{0}%
  \whiledo{\therecordindex<\datacellROWS}{%
    \stepcounter{recordindex}%
    \ifthenelse{\equal{#1}%
      {\datacell[\therecordindex,1]}}
    {\xdef\matchrecord{\therecordindex}\setcounter{recordindex}{\datacellROWS}}%
    {}%
  }%
}
\begin{document}
\readarraysepchar{,}
\readdef{database.csv}{\mydata}
\readarray\mydata\datacell[-,\ncols]

The whole array is\arraydump\datacell
\datacellROWS\ records total\par
\datacell[3,6] is the 6th cell of the 3rd row\par
\datacell[4,11] is the 11th cell of the 4th row\par
\findrecord{Sue}
\datacell[\matchrecord,4] is Sue's 4th data cell
\end{document}

I am removing my earlier solutions because they relied on use of internal code from my tabstackengine and readarray packages, which has changed in recent package updates.

Answer 3

Mostly by accident, I found a solution. The way I got it to work seems a bit long-winded, though, so I think there's probably a better way of doing it that I simply haven't figured out.

database.csv...

name,points,other
John,172,yes
Sue,120,no
Mike,64,maybe

document.tex...

\documentclass{memoir}
\usepackage{datatool}
\DTLloaddb{players}{database.csv}
\newcommand{\player}[1]{%
    \dtlgetrowforvalue{players}{\dtlcolumnindex{players}{name}}{#1}%
    \input{./template.tex}%
}
\begin{document}
\player{Sue}
\end{document}

template.tex...

% read variables into commands
\dtlgetentryfromcurrentrow{\name}{1}
\dtlgetentryfromcurrentrow{\points}{2}
\dtlgetentryfromcurrentrow{\other}{3}

% use commands in text
\subsubsection{\name}
\textit{\points}
\other