Merges an object's schemas with empty keys. The remaining such schema contains all attributes contained in such schemas.
merge_empty_keys(x)An R object of the same class as x, where relations with an
empty key have been merged into a single relation.
a relational schema object, such as a relation_schema
or database_schema object.
This function is not itself generic, but makes use of the generic functions
keys and merge_schemas. Any input class with
valid methods for these generic functions can be passed into this function.
For database_schema objects, references involving the
schemas with empty keys are updated to refer to the merged schema.
merge_schemas, on which this function is based.