datatool with longtable

Question

I have a CSV file that has many rows. I want to typeset these rows into a table using longtable and datatool package.

1. However just before before the "lastfoot" (which says concluded) I am getting an empty row which I do not want. How to remove that extra row?
2. The columns are not equally spaced under the dates. Somebody please help me to make them equally spaced.

I am giving the sample code. The name of my CSV file is namelist.csv and it looks like this.

    number,degree,Name
    1,Dr,Abdul Ali
    2,Mrs,Francesca Joestar
    3,Mr,Chan Ker Mei
    4,Dr,Hikaru Yagami
    5,Dr,Harish Kumar

My LaTeX code is below.

\documentclass[12pt]{article}
\usepackage{setspace}
\usepackage{bookman}
\usepackage{longtable}
\usepackage{pdflscape}
\usepackage[a4paper,left=1in,right=0.8in,top=0.5in,bottom=0.5in]{geometry}
\usepackage{tgschola}
\usepackage{microtype}
\usepackage{datatool}
\DTLloaddb{names}{namelist.csv}
%==================================================================
\begin{document}
%
\begin{landscape}
%
\doublespacing
%
\begin{longtable}{|l|l|c|c|r|r|r|c|c|c|c|c|c|c|c|c|c|c|}\hline
%
No.&\multicolumn{1}{c|}{Name}& \multicolumn{2}{c|}{13.12.2010}&  
\multicolumn{2}{c|}{14.12.2010}&\multicolumn{2}{c|}{15.12.2010}&
\multicolumn{2}{c|}{16.12.2010}
&\multicolumn{2}{c|}{17.12.2010}&\multicolumn{2}{c|}{18.12.2010}
&\multicolumn{2}{c|}{19.12.2010} &\multicolumn{2}{c|}{20.12.2010}\\ \hline\hline
\endfirsthead
%
\multicolumn{18}{c}%
{{\bfseries  Continued from previous page}} \\
\hline
%
No.&\multicolumn{1}{c|}{Name}& \multicolumn{2}{c|}{13.12.2010}&
\multicolumn{2}{c|}{14.12.2010}&\multicolumn{2}{c|}{15.12.2010}& 
\multicolumn{2}{c|}{16.12.2010}
&\multicolumn{2}{c|}{17.12.2010}&\multicolumn{2}{c|}{18.12.2010}
&\multicolumn{2}{c|}{19.12.2010} &\multicolumn{2}{c|}{20.12.2010}\\ \hline\hline
\endhead
%
\hline \multicolumn{18}{|r|}{{Continued on next page}} \\ \hline
\endfoot
%
\hline
\multicolumn{18}{|r|}{{Concluded}} \\ \hline
\endlastfoot
%
\DTLforeach{names}{
\no=number, \dg=degree, \name=Name}{
\no& \dg. \name &  & &  & &  & &  &
&  &  &  &  &  &  &  & \\ \hline
}
\end{longtable}%
%
\end{landscape}
%
\end{document}

Answer 1

When using \DTLforeach with \hline it's generally better to use the following schematic structure which puts the \\ and the \hline at the beginning of each non-initial row instead of at the end of each row.

\DTLforeach{<database>}{<assignments>}{%
\DTLiffirstrow{}{\\\hline}

 rest of table with no final \\
}

For your second problem, there may be different solutions, but the simplest may be to use a fixed column width. If the cells will always be blank, just a p{2em} column would be fine; if you will subsequently be inserting centred text in the cells, then you need a slightly more complicated version, which is what I've use in the example.

Using the array package, I've defined a C columnn:

\newcolumntype{C}{>{\centering\arraybackslash}p{2em}}

and used this as the basis for the main c columns.

So for your code specifically:

\documentclass[12pt]{article}
\usepackage{setspace}
\usepackage{longtable,array}
\usepackage{pdflscape}
\usepackage[a4paper,left=1in,right=0.8in,top=0.5in,bottom=0.5in]{geometry}
\usepackage{datatool}
\DTLloaddb{names}{namelist.csv}
%==================================================================
\begin{document}
%
\begin{landscape}
%
\doublespacing
%
\newcolumntype{C}{>{\centering\arraybackslash}p{2em}} % THIS COMMAND ADDED
\begin{longtable}{|r|l|C|C|C|C|C|C|C|C|C|C|C|C|C|C|C|C|} % THIS COMMAND CHANGED
\hline
%
No.&\multicolumn{1}{c|}{Name}& \multicolumn{2}{c|}{13.12.2010}&  
\multicolumn{2}{c|}{14.12.2010}&\multicolumn{2}{c|}{15.12.2010}&
\multicolumn{2}{c|}{16.12.2010}
&\multicolumn{2}{c|}{17.12.2010}&\multicolumn{2}{c|}{18.12.2010}
&\multicolumn{2}{c|}{19.12.2010} &\multicolumn{2}{c|}{20.12.2010}\\ \hline\hline
\endfirsthead
%
\multicolumn{18}{c}%
{{\bfseries  Continued from previous page}} \\
\hline
%
No.&\multicolumn{1}{c|}{Name}& \multicolumn{2}{c|}{13.12.2010}&
\multicolumn{2}{c|}{14.12.2010}&\multicolumn{2}{c|}{15.12.2010}& 
\multicolumn{2}{c|}{16.12.2010}
&\multicolumn{2}{c|}{17.12.2010}&\multicolumn{2}{c|}{18.12.2010}
&\multicolumn{2}{c|}{19.12.2010} &\multicolumn{2}{c|}{20.12.2010}\\ \hline\hline
\endhead
%
\hline \multicolumn{18}{|r|}{{Continued on next page}} \\ \hline
\endfoot
%
\hline
\multicolumn{18}{|r|}{{Concluded}} \\ \hline
\endlastfoot
%
\DTLforeach{names}{%
\no=number, \dg=degree, \name=Name}{%
\DTLiffirstrow{}{\\\hline}  % THIS LINE HAS BEEN ADDED
\no& \dg. \name & & &  & &  & &  &
&  &  &  &  &  &  &  & % THIS LINE HAS BEEN CHANGED
}
\end{longtable}%
%
\end{landscape}
%
\end{document} 

Answer 2

A blank line in LT is most likely from a spurious \\ somewhere. From your description it isn't clear if it is in the foot as an empty first row, or in the body of the table as an empty last row, these can look the same in the output, but of course are completely separate in the source.

Answer 3

Do not forget to add an % in this line. There is a difference from the following line

\DTLiffirstrow{}{\\\hline}  

to

\DTLiffirstrow{}{\\\hline}  % THIS LINE HAS BEEN ADDED

If you add the first line to your table sometimes an unexpected behavior will occure. The first entry of the database will ad a space on column 1, row 1.

If you add the second line (especially you should add at least the % sign) than this behaviour will be prevented.

It's only an additional info that I found out because of this case. I remembered this entry in case of this command and want to submit this info to the community.