Fix Set data to at least a blank array on Dataset::execute.
Fix Set data to at least a blank array on Dataset::execute.

This prevents blank query results from re-executing the query multiple times.

nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus,nicholasryan/CorePlus