Code I am trying to run:
$query = \"DESCRIBE TABLE TABLENAME\";
$result = odbc_exec($h, $query);
The result:
PHP War
To me it looks like you need to provide a way for the statement to return a value "Valid tokens: INTO" tells me that. I haven't used DESCRIBE before, but I would imagine that it returns something.
Interactive SQL doesn't allow the command so I can't really help you much further than that.
BTW, add the iSeries tag to your question. You might get a few more answers that way.