Chapter 5. Retrieving and Manipulating Database Objects
Chapter 4 discussed the definitions of various database objects, using the Data Definition Language (DDL). In this chapter, we start manipulating the database objects, using the portion of SQL known as Data Manipulation Language (DML). We populate (insert) data into the database and retrieve the data, using many powerful methods. Depending on their sophistication, the database users can use SQL to query the database. The majority of the SQL statements within a DB2 application involve DML statements. Therefore, application developers must understand the various methods of inserting, updating, and retrieving data from the database.
We start with simple retrieval statements and gradually introduce more complex methods of data manipulation. The DB2 Certification database will be used for most of the examples. The four main DML SQL statements we consider are SELECT, INSERT, UPDATE, and DELETE.