specified column width

Question

I'm using the following code for the table. Currently it is set up so that I can change the width of all column (except the first one) to the same width. Can someone help me tweet it so that I can specify the column width every time I use it? Thank you.

\documentclass[twoside]{book}

\usepackage{tikz}
%%table 
\usetikzlibrary{matrix}
\tikzset{ 
    table/.style={
        matrix of nodes,
        row sep=-\pgflinewidth,
        column sep=-\pgflinewidth,
        nodes={
            rectangle,
            draw=gray!50,
            align=center
        },
        minimum height=1.5em,
        text depth=0.5ex,
        text height=2ex,
        nodes in empty cells,
%%
        every odd row/.style={
            nodes={fill=gray!05}
        },
        column 1/.style={
          nodes={text width=5em,font=\bfseries}
        },
        row 1/.style={
            nodes={
                fill=gray!25,
                text=black,
                text height=2.5ex,
                font=\bfseries, purple!75!black
            }
        }
    }
}

\begin{document}

\begin{tikzpicture}
\matrix[table,text width=12em]
{
first & 2nd column   & 3rd column\\
&A & B \\
& C & D \\
};
\end{tikzpicture}

\end{document}

I want to put this in the preamble, but that means I have to have the all the tables in the same document to the same width specified, as of now.

Thank you.

Answer 1

Do you want something like this so that you can adjust the width of the first column as well as that of the other columns?

\documentclass{book}
\usepackage{tikz}
\usetikzlibrary{matrix}
\tikzset{
  table/.style={
    matrix of nodes,
    row sep=-\pgflinewidth,
    column sep=-\pgflinewidth,
    nodes={
      rectangle,
      draw=gray!50,
      align=center
    },
    minimum height=1.5em,
    text depth=0.5ex,
    text height=2ex,
    nodes in empty cells,
    %%
    every odd row/.style={
      nodes={fill=gray!05}
    },
    first column text width/.code={%
      \tikzset{
        column 1/.style={
          nodes={text width=##1, font=\bfseries}
        },
      }
    },
    first column text width=5em,
    row 1/.style={
      nodes={
        fill=gray!25,
        text=black,
        text height=2.5ex,
        font=\bfseries, purple!75!black
      }
    }
  }
}
\begin{document}

  \begin{tikzpicture}
    \matrix[table,text width=12em]
    {
      first & 2nd column   & 3rd column\\
      &A & B \\
      & C & D \\
    };
  \end{tikzpicture}

  \begin{tikzpicture}
    \matrix[table,text width=6em, first column text width=3em]
    {
      first & 2nd column   & 3rd column\\
      &A & B \\
      & C & D \\
    };
  \end{tikzpicture}
\end{document}