database-integrity

In Rails 2.x you can use validations to make sure you have a unique combined value like this: validates_uniqueness_of :husband, :scope => :wife In the corresponding migration it could look like this: add_index :family, [:husband, :wife], :unique => true This would make sure the husband/wife combination is unique in the database. Now, in Rails 3 the validation syntax changed and the scope attribute seems to be gone. It now looks like: validates :husband, :presence => true Any idea how I can achieve the combined validation in Rails 3? The Rails 2.x validations still work in Rails 3 so I can

I'm at a client doing some quick fixes to their access application. It was a while I had a go with access, but I'm recovering quickly. However, I've discovered an interesting problem: For some reports, I get a "Record is deleted" error. I've checked the reports, and it seems like there's a problem with one table. When opening that table, I find a record where all columns are marked "#deleted". So obviously, this row seems to be the culprit. However, when I try to delete that row, nothing really happens. If I re-open the table, the row still exists. Is there a corruption in the db? How can I

It seems that some scripts generated by Enterprise Manager* (or not, it doesn't matter) created check constraints WITH NOCHECK . Now when anyone modifies the table, SQL Server is stumbling across failed check constraints , and throwing errors. Can i make SQL go through all its check constraints, and check them? Running: sp_msforeachtable 'ALTER TABLE ? CHECK CONSTRAINT all' only enables previously disabled check constraints, it doesn't actually check them. Footnotes * SQL Server 2000 Nathan DBCC CHECKCONSTRAINTS WITH ALL_CONSTRAINTS won't actually make your constraints trusted. It will report

I'm following up in regards to a question that I asked earlier in which I sought to seek a conversion from a goofy/poorly written mysql query to postgresql. I believe I succeeded with that. Anyways, I'm using data that was manually moved from a mysql database to a postgres database. I'm using a query that looks like so: """ UPDATE krypdos_coderound cru set is_correct = case when t.kv_values1 = t.kv_values2 then True else False end from (select cr.id, array_agg( case when kv1.code_round_id = cr.id then kv1.option_id else null end ) as kv_values1, array_agg( case when kv2.code_round_id = cr_m.id