I've long used the
db_multirow foo bar { select email, '' as url from cc_users } {
set url "..."
}
hack in order to add computed columns to my multirow.
Well, now there's a slightly cleaner way which doesn't involve
asking the DB to add them for us in this ugly way: db_multirow -
extend. Just say:
db_multirow -extend { url } foo bar { select email from cc_users } {
set url "..." }
At the same time, I fixed db_multirow so it sets the foo:columns
variable to the column list properly. This is useful if you want to
later do a template::multirow extend.
Also, while doing this, I removed the hack where db_multirow would
regsub all occurences of "foo" (the multirow name)
to "foo:1", "foo:2", etc. (foo:rownum).
This was done so that you could add columns to the multirow in this
way, by saying set foo(url) "..." which would then be translated
into "set foo:1(url)" ...".
Now, you just say -extend { url } and then in the code block you say
set url "...", and the local variable url is automatically put into
the multirow for you.
The also works with -append, with the caveat that -extend doesn't
have any effect with an -append switch. Instead, if uses the columns
that it got from the first db_multirow, the one without the -append.
I encourage you to still specify -extend on calls with -append, for
documentation.
I think this behavior makes sense: When you append to a multirow,
you shouldn't be changing the schema.
Again, ask Don when this'll get into the tree.
Comments and feedback?
