Imtiaz Ul Haq, 58, suffered serious knife wounds to his throat during the attack at the Costcutter convenience store in Queensferry on 8 December
At Mold Crown Court on Monday, Matthew Liam Whelan, 29, from Mancot, denied attempted murder but admitted both wounding with intent and robbery.
Leslie Peter Baines, 47, of Connah's Quay, denies the robbery charge.
A trial date has been set for 22 May, however the prosecution has been asked to consider if it wishes to proceed with an attempted murder charge against Whelan or accept his guilty plea to the other offence.
Both men were remanded in custody ahead of a pre-trial hearing in April.
A man accused of trying to kill a Flintshire shopkeeper in a robbery has admitted a wounding charge.