Btukfyl

I'm trying to draw a database dependency diagram, similar to the one shown below

(Gaaah! I can't upload images. ASCII art it is then...)

  +------+------+------+------+------+------+

  |      |      |      |      |      |      |

  |      v      |      v      v      v      v

+---+  +---+  +---+  +---+  +---+  +---+  +---+      Lines extend from 1 and 3,

| 1 |  | 2 |  | 3 |  | 4 |  | 5 |  | 6 |  | 7 |      join above 2, and then route

+---+  +---+  +---+  +---+  +---+  +---+  +---+      to all other blocks

I've managed to get the easy bits done, namely drawing the blocks. I assume that I need to create a number of control points that the arrows must move through to 'raise' them above the nodes. What I can't get is to have them drawn nice and square.

Theres also the problem of the junction point above PROJ_NAME (block 2). PROJ_NUM (block 1) and EMP_NUM (block 3) together form a junction, and this junction joins to all the others. My Tikz attempt (although visually very far from what I want) illustrates this (I think?)

Please could someone point me in the right direction? Am I on the right track, is there a way easier method of doing this?

tikzstyle{line} = [draw, -latex']

tikzstyle{block} = [rectangle, draw, text centered, rounded corners, 

    minimum height=1.5em,font=tiny]

tikzstyle{cntrl} = [node distance=2em, minimum height=0]



begin{tikzpicture}

    [shorten >=1pt,node distance=0.1em,auto,scale=0.5]        



    node[block]    (n1)                     {PROJ_NUM};

    node[block]    (n2)  [right =of n1]     {PROJ_NAME};

    node[block]    (n3)  [right =of n2]     {EMP_NUM};                                         

    node[block]    (n4)  [right =of n3]     {EMP_NAME};

    node[block]    (n5)  [right =of n4]     {JOB_CLASS};

    node[block]    (n6)  [right =of n5]     {CHG_HOUR};

    node[block]    (n7)  [right =of n6]     {HOURS};



    node[cntrl]    (i1)     [above =of n1]                  {};

    node[cntrl]    (i2)     [above =of n2]                  {};

    node[cntrl]    (i3)     [above =of n3]                  {};

    node[cntrl]    (i4)     [above =of n4]                  {};

    node[cntrl]    (i5)     [above =of n5]                  {};

    node[cntrl]    (i6)     [above =of n6]                  {};

    node[cntrl]    (i7)     [above =of n7]                  {};



    path [line] (n1) .. controls (i1) and (i2) .. (n2);

    path [line] (n3) .. controls (i3) and (i2) .. (n2);

    path [line] (i2) .. controls (i2) and (i4) .. (n4);

    path [line] (i2) .. controls (i2) and (i5) .. (n5);

    path [line] (i2) .. controls (i2) and (i6) .. (n6);

    path [line] (i2) .. controls (i2) and (i7) .. (n7);



end{tikzpicture}    

Links to diagrams that I uploaded. Hopefully the links remain active..

Attempt so far:

I read about the rectangle split node yesterday, so this was a chance to experiment. The code is far from perfect, but a good starting point:

documentclass[parskip]{scrartcl}

usepackage[margin=15mm,landscape]{geometry}

usepackage{tikz}

usetikzlibrary{shapes.multipart, calc}



begin{document}

begin{tikzpicture}[my shape/.style={

rectangle split, rectangle split parts=#1, draw, anchor=center}]

node [my shape=7, rectangle split horizontal,name=dedi, rectangle split part fill={olive!50, blue!70, olive!50, blue!70}]  at (0,0)

{PROJ_NUM%

nodepart{two}   PROJ_NAME

nodepart{three} EMP_NUM

nodepart{four}  EMP_NAME

nodepart{five}  JOB_CLASS

nodepart{six}   CHG_HOUR

nodepart{seven} HOURS};



draw[latex-latex, very thick, red!70!black] (dedi.two north) -- ++(0,1) -| (dedi.four north);

draw[latex-latex, very thick, red!70!black] (dedi.five north) -- ++(0,1) -| (dedi.four north);

draw[latex-latex, very thick, red!70!black] (dedi.six north) -- ++(0,1) -| (dedi.four north);

draw[latex-latex, very thick, red!70!black] (dedi.seven north) -- ++(0,1) -| (dedi.four north);

draw[very thick, red!70!black]              (dedi.one north) -- ++(0,0.5) -| (dedi.three north);

draw[-latex, very thick, red!70!black]      (dedi.one south) -- ++(0,-0.5) node[below right, text width=3cm] {scriptsize partial dependancy} -| (dedi.two south);

draw[-latex, very thick, red!70!black]      ($(dedi.five south) + (0.2,0)$) -- ++(0,-0.5) node[below right, text width=2cm] {scriptsize Transitive dependancy} -| ($(dedi.six south) + (-0.2,0)$);

draw[-latex, very thick, red!70!black] (dedi.three south) -- ++(0,-2) -| (dedi.four south);

draw[-latex, very thick, red!70!black] (dedi.three south) -- ++(0,-2) -| (dedi.five south);

draw[-latex, very thick, red!70!black] (dedi.three south) -- ++(0,-2) -| node[below left] {scriptsize partial dependancies} (dedi.six south);

draw[-latex, very thick, red!70!black] (dedi.three south) -- ++(0,-2) -| (dedi.seven south);



end{tikzpicture}

end{document}

Have you seen the announcement of the tikz-dependency package in comp.text.tex?

http://www.ctan.org/pkg/tikz-dependency

The style used in Fundamentals of Database Systems by Elmasri and Navathe (ISBN-10: 0136086209) to draw functional dependencies is the following:

It is relatively easy to reproduce using tikz-dependency:

documentclass[border=20pt]{standalone}

renewcommandfamilydefault{sfdefault}

usepackage{tikz-dependency}

begin{document}



    depstyle{lvl1}{edge height=3ex, edge below, edge horizontal padding=0}

    depstyle{lvl2}{edge height=3ex, edge below, edge vertical padding=4ex}

    depstyle{lvl3}{edge height=3ex, edge below, edge vertical padding=8ex}





begin{dependency}[%

    text only label,% No need for label for functional dependencies

    edge slant=0, % We want right angles

    edge style={>=triangle 60} % change the style of the arrowheads

    ]

    begin{deptext}[column sep=0.4cm] % Adding some distance between the attributes

        Ename & underline{Ssn} & BDate & Address & Dnumber & Dname & Dmgr_ssn \

    end{deptext}

    depedge[lvl1]{2}{1}{}

    depedge[lvl1]{2}{3}{}

    depedge[lvl1]{2}{4}{}

    depedge[lvl1]{2}{5}{}

    depedge[lvl2]{5}{6}{}

    depedge[lvl2]{5}{7}{}

end{dependency}





begin{dependency}[text only label, edge slant=0, edge style={>=triangle 60}]

    begin{deptext}[column sep=0cm,  nodes={fill=gray!20,draw=black, inner xsep= 3ex, inner ysep = 1ex}] % Styling of the attributes nodes.

        underline{Ssn} & underline{Pnumber} & Hours & Ename & Pname & Plocation \

    end{deptext}

    depedge[lvl1]{1}{3}{}

    depedge[lvl1]{2}{3}{}

    depedge[lvl2]{1}{4}{}

    depedge[lvl3]{2}{5}{}

    depedge[lvl3]{2}{6}{}

end{dependency}



end{document}

produces:

and (closer to the style used in the textbook)

I'm sure tikz purist will find a lot could be done to improve this code, but I thought I would share it with you, since it can help you in getting started.