Generally, you should no longer need to provide a custom tbl() method. The default tbl.DBIConnect method should work in most cases.

tbl_sql(subclass, src, from, ..., vars = NULL)

Arguments

subclass

name of subclass

...

needed for agreement with generic. Not otherwise used.

vars

Provide column names as a character vector to avoid retrieving them from the database. Mainly useful for better performance when creating multiple tbl objects.