How to put serial number in attendance sheet?

Question

Here (Automatic table row numbers) they shows automatic table row numbering. But, there they made the table manually and applied the technique.

When I make a attendance sheet I can make the sheet by looping. So, then how can I give the serial number in the table?

My sample code is -

\documentclass{article}
\usepackage{forloop}
\usepackage[a4paper,left=0cm,top=0cm]{geometry}
\newcommand{\aline}{\\\hline &&&&&&&&&&&&&&&&\rule{0cm}{.4cm}}
\begin{document}
\newcounter{theyflines}
\begin{tabular}{|p{0.20cm}|p{2.75cm}|p{1cm}|p{1cm}|p{.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{2.60cm}|p{1.30cm}|p{1.30cm}|}
\hline
SL&Name& Room&Dept.&L&D&B&L&D&B&L&D&B&L&Deposit&Cost&Extra
\forloop{theyflines}{1}{\value{theyflines} < 48}{\aline}\\
\hline
\end{tabular}
\end{document}

output -

My expected output -

Answer 1

For each line you print \aline, but you have not entered any contents of the cells. Just put \arabic{theyflines} in the first cell of the row:

\documentclass{article}
\usepackage{forloop}
\usepackage[a4paper,left=0cm,top=0cm]{geometry}
\newcommand{\aline}{\\\hline \arabic{theyflines} &&&&&&&&&&&&&&&&\rule{0cm}{.4cm}}
\begin{document}
\newcounter{theyflines}
\begin{tabular}{|p{0.20cm}|p{2.75cm}|p{1cm}|p{1cm}|p{.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{0.35cm}|p{2.60cm}|p{1.30cm}|p{1.30cm}|}
\hline
SL&Name& Room&Dept.&L&D&B&L&D&B&L&D&B&L&Deposit&Cost&Extra
\forloop{theyflines}{1}{\value{theyflines} < 48}{\aline}\\
\hline
\end{tabular}
\end{document}