How to determine whether the database libraries and tables exist?

Question

As the question goes, how to determine whether the database libraries and tables exist?

Answer 1

if exists(select*from sysobjects where name ='bbsUsers' )
drop table bbsUsers

bbsUsers is the table to be queried

sysobjects is the system table

Answer 2

You have an operation to connect to the database in the program. If there is no table or library, there will be an error message