What is the difference between read_sql() and read_sql_query()?
read_sql() is a function created for convenience that may call
read_sql_table() depending on the input we provide.
This function is a convenience wrapper around
read_sql_query(for backward compatibility). It will delegate to the specific function depending on the provided input. A SQL query will be routed to
read_sql_query, while a database table name will be routed to
read_sql_table. Note that the delegated function might have more specific notes about their functionality not listed here.