Question

I have the following code:

<%@submission_general = ActiveRecord::Base.connection.select_all('SELECT * FROM DBASE_general.submission')%>

<%=  @submission_general.count%> -- gives 11,000 entries

<%=  @submission_general[1].sub_id%> -- gives undefined method `sub_id' for #<Hash:0xb4a01108>

Where have I gone wrong?

Thanks a lot for your help

Answer 1

As per documentation, ActiveRecord::Base::select_all returns an array of hashes, not an array of models. I guess you wanted to write something like Submission.all, which would generate the same SQL (having it bound to a table submission in DBASE_general database).

In case because of some reason it is undesired to have a model for that table (maybe you want to save some memory, or the table name is not known in advance etc), you have to address the results as hashes of pairs column_name / value, so you would use something like:

@submission_general = ActiveRecord::Base.connection.select_all('SELECT * FROM DBASE_general.submission')
@submission_general[1]["sub_id"]

However, the above approach has lots of flaws, so you’d better use models if you can.