Chris Fehily Quotes & Sayings

Microsoft SQL Server, Oracle, DB2, and PostgreSQL let you create user-defined types (UDTs). The simplest UDT is a standard or built-in data type (CHARACTER, INTEGER, and so on) with additional check and other constraints. You can define the data type marital_status, for example, as a single-character CHARACTER data type that allows only the values S, M, W, D, or NULL (for single, married, widowed, divorced, or unknown). More-complex UDTs are similar to classes in object-oriented programming languages such as Java or Python. You can define a UDT once and use it in multiple tables, rather than repeat its definition in each table in which it's used. Search your DBMS documentation for user-defined type. UDTs are created in standard SQL with the statement CREATE TYPE. — Chris Fehily