Question

I have a Sinatra app utilizing Sequel and Postgres… it’s a very simple module that inserts into a database. I want to capture any errors from the insert and return a useful message.

My codes is as follows:

begin
   sql = DB["INSERT INTO table (id, firstname, lastname, ...) values (......)"]
   ds.insert
rescue Sequel::Error
   ...
end

How do I capture what the actual error is? I can put “There was an error” and that is printed, but I want something more specific – like “First name is required”, “Last name is required”.

Can someone help?

Answer 1

You can use the last exception object magic constant $!:

rescue Sequel::Error
  p $!.message
end

Also you can change the rescue block to put the exception object into a variable:

rescue Sequel::Error => e
  p e.message
end

Both would print the exception messsage.