Graphviz dot: How to change the colour of one record in multi-record shape

Question

I have the following dot sample. I would like to give the first section in each record (the table name) a different background and foreground colour. I can't find any examples of how to do this for a record. Basically I want the table name in the sql query schema diagram to stand out. Can anyone help?

digraph G {
   rankdir=LR;
   node [shape=record];
   corpus_language [label="corpus_language|<id> id\len\l|<name> name\lEnglist\l|<sentence_count> sentence_count\l1027686\l"];
   corpus_sentence [label="corpus_sentence|<id> id\l1241798\l|<text> text\lBaseball is a sport\l|<creator_id> creator_id\l10859\l|<created_on> created_on\l2006-11-14 17:58:09.303128\l|<language_id> language_id\len\l|<activity_id> activity_id\l11\l|<score> score\l124\l"];   
   corpus_language:id -> corpus_sentence:language_id [arrowhead=normal label=language_id];   
}

Answer 1

I'm pretty sure that it's not possible. Instead you should use HTML-style labels, that are a more developped form of record nodes. You can define your node using the <table> tag, and set the color using bgcolor="your_color". A list of available colors is available here: http://www.graphviz.org/doc/info/colors.html (you also have a RGBA way of doing it, as described here: http://www.graphviz.org/doc/info/attrs.html#k:color)

With HTML labels, your example becomes as follows:

digraph G
{
    rankdir = LR;
    node1
    [
        shape = none
        label = <<table border="0" cellspacing="0">
                    <tr><td port="port1" border="1" bgcolor="red">corpus_language</td></tr>
                    <tr><td port="port2" border="1">id: en</td></tr>
                    <tr><td port="port3" border="1">name: Englist</td></tr>
                    <tr><td port="port4" border="1">sentence_count: 1027686</td></tr>
                </table>>
    ]
    node2
    [
        shape = none
        label = <<table border="0" cellspacing="0">
                    <tr><td port="port1" border="1" bgcolor="blue">corpus_sentence</td></tr>
                    <tr><td port="port2" border="1">id: 1241798</td></tr>
                    <tr><td port="port3" border="1">text: Baseball is a sport</td></tr>
                    <tr><td port="port4" border="1">creator_id: 10859</td></tr>
                    <tr><td port="port5" border="1">created_on: 2006-11-14 17:58:09.303128</td></tr>
                    <tr><td port="port6" border="1">language_id: en</td></tr>
                    <tr><td port="port7" border="1">activity_id: 11</td></tr>
                    <tr><td port="port8" border="1">score: 124</td></tr>
                </table>>
    ]
    node1:port2 -> node2:port6 [label="language_id"]
}

Here is the result: