Set many database columns NOT NULL

{election_vote} does not need to store election_id or post_id. It can get those by joining to {election_ballot}.

Please allow for the possibility of setting election_vote.ballot_id NULL, and still being able to count votes. It's to theoretically allow counting the entire election's votes without having any trace of who voted, which means you could support #2006326: Make election_vote records anonymous if you wanted. So, that's also why election_vote.ballot_id should not be NOT NULL.

I'm OK with the rest.

There are probably excessive indexes on some tables.

I certainly would not make these database schema choices again if redesigning the module.

However, this is a complex and relatively risky patch, which could break existing installs if they had set these columns NULL before (for whatever reason).

So we'd at least need a clear explanation of the practical benefits.

1. +++ b/election.install
   @@ -32,13 +32,13 @@ function election_schema() {
          'uid' => array(
            'description' => 'The {users}.uid of the election\'s owner/creator.',
            'type' => 'int',
            'unsigned' => TRUE,
   -        'not null' => FALSE,
   +        'not null' => TRUE,
   

   To me this would imply that if a user is deleted, all their elections must be deleted. I don't think site owners necessarily want that.

2. +++ b/election.install
   @@ -107,7 +102,7 @@ function election_schema() {
          'changed' => array(
            'description' => 'The Unix timestamp for when the election was most recently changed.',
            'type' => 'int',
   -        'not null' => FALSE,
   +        'not null' => TRUE,
   

   Philosophically at least, NULL here would mean that the election has not been changed since it was created.

3. +++ b/election_candidate/election_candidate.install
   @@ -26,13 +26,13 @@ function election_candidate_schema() {
            'description' => 'The post for which the candidate is standing. Relates to {election_post}.post_id.',
            'type' => 'int',
            'unsigned' => TRUE,
   -        'not null' => FALSE,
   +        'not null' => TRUE,
   

   Candidates are not deleted when posts are deleted - this is explicitly set to NULL in election_candidate_entity_delete().

I suggest documentation (#2621482: Document NULLs in schema) is more important than actually setting these NOT NULL.