Table: remove automatic row number for label

Question

When creating a long table in my document, I add the automatic row number for each row. However, when I add the label for my table, it shows a blank row with the automatic row number, like this.

Here is the minimal example code:

\documentclass{article}

\usepackage{tabu,longtable}
\newcounter{rowno}

\begin{document}
    \begin{longtabu} {|c<{\stepcounter{rowno}\therowno}|X|X|X|}
        \caption{testtable} \\ 
        \hline
        \multicolumn{1}{|c|}{No.} & \multicolumn{1}{c|}{rule} & \multicolumn{1}{c|}{example} & \multicolumn{1}{c|}{src} \\ \hline
         & content & content2 & content3 \\ \hline
        \label{table:test} \\
    \end{longtabu}
\end{document}

It's really strange. Why does it add the auto rowno to the label row? And more incomprehensible to me, why would the label count as a row?

Answer 1

If you put your \label{} after your caption (where it really ought to be), then the additional row disapears:

\documentclass{article}

\usepackage{tabu,longtable}
\newcounter{rowno}

\begin{document}
    \begin{longtabu} {|c<{\stepcounter{rowno}\therowno}|X|X|X|}
        \caption{testtable}\label{table:test} \\ 
        \hline
        \multicolumn{1}{|c|}{No.} & \multicolumn{1}{c|}{rule} & \multicolumn{1}{c|}{example} & \multicolumn{1}{c|}{src} \\ \hline
         & content & content2 & content3 \\ \hline
    \end{longtabu}
\end{document}