Furthermore, the unique constraint columns may be set to null. Data type and data length are the most fundamental integrity constraints applied to data in the database. Simply by specifying the data ...

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 ...

A constraint checks the values you insert or update in a table against the conditions specified by the constraint. For example, a constraint could ensure that the value entered for the column GENDER ...