OLE DB

People often ask which data access method is best to use for developing database applications. The answer to that question depends the type of database you are connecting to, and the functionality the application requires. This lesson introduces the DAO, RDO, ADO, and SQL-DMO data access methods, and describes how to connect to a database and return a result set using each type.

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After completing this lesson, you will be able to:

• Compare and contrast Data Access Objects (DAO), Remote Data Objects (RDO), and ActiveX Data Objects (ADO).
• Explain the implementation considerations for the most common data access interfaces.
• Connect to a data source and return records using DAO, RDO, and ADO.
• Describe the function of SQL-DMO.

Estimated lesson time 90 minutes

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DAO, RDO, ADO and SQL-DMO are data access methods built to retrieve and manipulate data in relational databases. The models perform similar functions; however, each is optimized for a specific situation. For example, you would use DAO to manipulate records on a local Microsoft Access database, but you would use RDO to manipulate records on a SQL Server database. In addition, each method executes through a different API or database engine.

Before you continue with the lesson, run the Chap07.exe animation located on the CD-ROM that accompanies this book. This animation introduces the data access method available to developers.

Figure 7.1 Database Interfaces for Developers