Append to JuliaDB tables in a Dict

I have this dictionary on nsparce tables.

general_ledger=Dict(
		   #:description => ndsparse(date=date, memo=memo),
           :dividends => ndsparse((debit=x, 
			credit=y), 
		(balance=z,)),
		   :expenses => ndsparse((debit=x, 
			credit=y),
		(balance=z,)),
		   :assets  => ndsparse((debit=x, 
			credit=y),
		(balance=z,)),
	       :liablities => ndsparse((debit=x, 
			credit=y),
		(balance=z,)),
           :equity => ndsparse((debit=x, 
			credit=y),
		(balance=z,)),
		   :revenue => ndsparse((debit=x, 
			credit=y),
		(balance=z,))
			)

and I want to add a new row

			default_values=Dict(
								"dividends"=>ndsparse((
														debit=[0], 
														credit=[0]), 
														(balance=[0],)),
								"expenses"=>ndsparse((
														debit=[0], 
														credit=[0]), 
														(balance=[0],)),
								"assets"=>ndsparse((
														debit=[0], 
														credit=[0]), 
														(balance=[0],)),
								"libilites"=>ndsparse((
														debit=[0], 
														credit=[0]), 
														(balance=[0],)),
								"equity"=>ndsparse((
														debit=[0], 
														credit=[0]), 
														(balance=[0],)),
								"revenue"=>ndsparse((
														debit=[0], 
														credit=[0]), 
														(balance=[0],)))
	
			spec = Dict( 
				credit_account =>ndsparse((
														debit=[0], 
														credit=[credit_amount]), 
														(balance=[0],)), 
				debit_account => ndsparse((
														debit=[debit_amount], 
														credit=[0]), 
														(balance=[0],)))
			modified! = merge!(default_values, spec)
		
			merge(general_ledger, modified!)

instead of adding a row to each nsparse table, it creates new entries.