I am of the firm belief that in an Entity Relation Diagram, the entity should be reflected with a singular name, similar to a class name being singular. Once instantiated, the name reflects its instance. So with databases, the entity when made into a table (a collection of entities or records) is plural. Entity, User is made into table Users. I would agree with others who suggested maybe the name User could be improved to Employee or something more applicable to your scenario.
This then makes more sense in a SQL statement because you are selecting from a group of records and if the table name is singular, it doesn't read well.