DBCC CHECKCONSTRAINTS - Check the integrity of table constraints.

Syntax
      DBCC CHECKCONSTRAINTS
         [('table' | table_id | 'constraint' | constraint_id) ]
            [WITH 
               [ { ALL_CONSTRAINTS | ALL_ERRORMSGS } ]
                  [ , ] [ NO_INFOMSGS ] 
            ]
 Key:
   ALL_CONSTRAINTS - Check disabled constraints in addition to enabled constraints 
                     has no effect when a constraint name is specified.
   ALL_ERRORMSGS   - Return all rows that violate constraints in the table being checked.
                     default = first 200 rows.

"The practice of both mathematics and art requires a blend of discipline and vision--a delicate balancing of constraint and freedom" ~ Ivars Peterson

Related

DBCC CHECKTABLE - Check integrity of a table or indexed view.

Equivalent Oracle commands:

ALTER TABLE MODIFY CONSTRAINT VALIDATE