CODEWITHSUNDEEP
ruby-on-railsrubyactiverecord
user94154
user94154

Reputation: 16574

missing attribute in activerecord

I have models Foo and Bar. Bar has column foo_id. When I call Bar.foo_id I get the error missing attribute: foo_id

Keep in mind that this is not an undefined method error and the column definitely is in the db. What are some common causes of this?

Thanks

Upvotes: 15

Views: 16881

Answers (3)

Arta
Arta

Reputation: 5196

This happens to me now and then. My cause is almost always a long forgotten finder method on a class that specifies fields in .select() and the missing attribute (often added long after I had the finder defined) is now invoked somewhere in the app but not specified in that .select().

The error is common enough to have earned an alert in the Rails Guides: "Be careful because ... "

Upvotes: 2

Staelen
Staelen

Reputation: 7841

Probably it has something to do with your find method? For instance you did a :select in a find:

Foo.find(:all, :select => "firstvar, secondvar")

In that case, you can only access firstvar and secondvar even though you have foo_id defined

Hope it helps! =)

Upvotes: 45

theIV
theIV

Reputation: 25794

Are you calling

Bar.foo_id

or

bar = Bar.new
bar.foo_id

Unless you have a class variable for Bar, you need to look at foo_id on an instance of Bar. I hope that helps. Cheers.

Upvotes: 2

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