dbcc checkdb runs the same checks as dbcc checktable on each table in the specified database. If you do not give a database name, dbcc checkdb checks the current database. dbcc checkdb gives similar messages to those returned by dbcc checktable and makes the same types of corrections.
The syntax for dbcc checkdb is:
dbcc checkdb [(database_name [, skip_ncindex]) ]
If you specify the optional skip_ncindex, dbcc checkdb does not check any of the nonclustered indexes on user tables in the database.