I am writing a function to extract data either from a table or a query
and output it in xml. I have the logic down, but I cannot work out a
few things.
1. How can I read the column headings from the returned data set? I
have resorted to writing the same function in tcl in which I can work
out how to do this, but what about pgsql? I can't use the system tables
for this, since the data may not come from a table.
2. It it possible, either in tcl or pgsql, to have optional function
arguments?