Create a SparkDataFrame from a SparkSQL table or view
Returns the specified table or view as a SparkDataFrame. The table or view must already exist or have already been registered in the SparkSession.
the qualified or unqualified name that designates a table or view. If a database is specified, it identifies the table/view from the database. Otherwise, it first attempts to find a temporary view with the given name and then match the table/view from the current database.