DDL, DML, and programmable objects

As a developer, you are often also responsible to create database objects. Of course, in an application, you also need to insert, update, and delete the data. In order to maintain data integrity, enforcing data complies with business rules, you need to implement constraints. In a quick review of the data definition language (DDL) and data modification language (DML) elements, the following statements are presented:

• CREATE for creating tables and programmatic objects
• ALTER to add constraints to a table
• DROP to drop an object
• INSERT to insert new data
• UPDATE to change existing data
• DELETE to delete the data

In a SQL Server database, you can also use programmatic objects. You can use triggers for advanced constraints or to maintain redundant data like aggregated data. You can use other programmatic objects for data abstraction, for an intermediate layer between the actual data and an application. The following programmatic objects are introduced here:

• Triggers...