rails passing null values when creating using AR create method - ruby-on-rails

Question

In my rails application, I have a button which when clicked, copies data from one database and insert it in another.
I am using octopus gem to link my application to 2 databases.
To copy a record from db_A to db_B, I am using the code below:
Octopus.using(:shard_B) do
#book_new_live = Book.create(
:BK_SUB_FK => #book.BK_SUB_FK,
:BK_TITLE => #book.BK_TITLE,
:BK_SOURCE => "",
:BK_PUB => "",
:BK_COVER => "",
:BK_LABEL_PRODUCT => #book.BK_LABEL_PRODUCT,
:BK_FINAL_LABEL => "",
:BK_VISUAL_METHOD => #book.PRB_VISUAL_METHOD,
:BK_DB => "",
:BK_COVERED_REGION => "",
:BK_VERSION_NO => #book.BK_VERSION_NO,
:BK_SEQ_FILE => "",
)do |primary|
primary.BK_ID = #book.BK_ID
end
end
Database 'db_b', to which data in copied, does not accept null values and the columns cannot be null and the default value is 'NONE'.
Also, I am not allowed to modify the structure of the database so that it can accept null values.
If I use the simplified code below, I get an error message which informs me that the columns 'BK_SOURCE', 'BK_PUB', 'BK_COVER'...cannot be null. By default rails is passing null to those columns.
So I have to pass empty strings to the columns which cannot be null.
Octopus.using(:shard_B) do
#book_new_live = Book.create(
:BK_SUB_FK => #book.BK_SUB_FK,
:BK_TITLE => #book.BK_TITLE,
:BK_LABEL_PRODUCT => #book.BK_LABEL_PRODUCT,
:BK_VISUAL_METHOD => #book.PRB_VISUAL_METHOD,
:BK_VERSION_NO => #book.BK_VERSION_NO,
)do |primary|
primary.BK_ID = #book.BK_ID
end
end
Is there a way of preventing rails from passing null values to the columns not mentioned in the above code?

Answer 1

If i understand you correctly, you can just use the or operator to send your values like this:
Octopus.using(:shard_B) do
#book_new_live = Book.create(
:BK_SUB_FK => #book.BK_SUB_FK,
:BK_TITLE => #book.BK_TITLE,
:BK_SOURCE => #book.BK_SOURCE || "NONE",
:BK_PUB => #book.BK_PUB || "NONE",
:BK_COVER => #book.BK_COVER || "NONE",
:BK_LABEL_PRODUCT => #book.BK_LABEL_PRODUCT,
:BK_FINAL_LABEL => "",
:BK_VISUAL_METHOD => #book.PRB_VISUAL_METHOD,
:BK_DB => "",
:BK_COVERED_REGION => "",
:BK_VERSION_NO => #book.BK_VERSION_NO,
:BK_SEQ_FILE => "",
)do |primary|
primary.BK_ID = #book.BK_ID
end
end
By saying that the value to be passed is #book.BK_SOURCE || "NONE", if the attribute is nil, then the string NONE is passed instead.
EDIT
hash = {
:BK_SUB_FK => #book.BK_SUB_FK,
:BK_TITLE => #book.BK_TITLE,
:BK_SOURCE => #book.BK_SOURCE,
:BK_PUB => #book.BK_PUB,
:BK_COVER => #book.BK_COVER,
:BK_LABEL_PRODUCT => #book.BK_LABEL_PRODUCT,
:BK_FINAL_LABEL => #book.BK_FINAL_LABEL,
:BK_VISUAL_METHOD => #book.PRB_VISUAL_METHOD,
:BK_DB => #book.BK_DB,
:BK_VERSION_NO => #book.BK_VERSION_NO
}
hash = hash.delete_if { |k, v| v.nil? }
Octopus.using(:shard_B) do
#book_new_live = Book.create(hash)do |primary|
primary.BK_ID = #book.BK_ID
end
end
Give it a try.