Unique constraints differ from primary key constraints in that they cannot be used to support referential constraints. Furthermore, the unique constraint columns may be set to null. Data type and data ...

Check constraints are supported in all of the major DBMS products, including DB2, Oracle, and SQL Server. But they are too-often ignored and not implemented in production databases. Properly defined, ...

Referential constraints, which allow you to link the data values of the variables in one data file to specific variables in another data file. An example of a referential constraint would be linking ...

When I am working with an Oracle database, I still find myself using SQL*Plus for many quick and dirty database queries. In particular, I often look up constraints in SQL*Plus. In this post, I ...

Using Marten, it's possible to enforce the referential integrity between the Player and Kingdom. There are two methods to accomplish this. Configuring Referential Integrity with Attributes The first ...

Any non-referential integrity constraints defined for the input data set are inherited by the output data set unless there are indexes defined on the input data set, then no integrity constraints are ...