Wiley 978-0-7645-8437-4 Datasheet

History of Data AccessOver the years, many APIs have been released, all of which work toward the goal of providing universal data access. Universal da

In addition to all of the great advancements ADO made, it too had some shortcomings, of course. Forexample, even though it supported working with disc

With ADO.NET, the days of the recordset and cursor are gone. The model is entirely new, and consists offive basic objects:❑ Connection — The Connectio

In the 2.0 Framework, Microsoft has also been able to improve performance by introducing several newfeatures to reduce the number of queries that need

❑ Vendor commitment — Without the widespread buy-in of vendors to build drivers/providersfor their products, any universal data access model wouldn’t

❑ A syntax for defining a schema❑ A syntax for defining a subschema❑ A data manipulation languageThese concepts were later incorporated into the COBOL

The Ingres project was backed by several U.S. military research agencies and was very similar to System Rin many ways, although it ran on a different

OLE-DBObject Linking and Embedding Database (OLE-DB) was the next big step forward in data providers, and itis still widely used today. With OLE-DB, M

Figure 1-1Data Access ConsumersDevelopers who use languages that support pointers — such as C, C++, VJ++, and so on — can speakdirectly to the ODBC an

Figure 1-2The main problem with DAO is that it can only talk to the JET engine. The JET engine then communicateswith ODBC to retrieve the data. Going

ODBCDirect, a DAO add-on that routed the ODBC requests through RDO instead of the JET engine, theperformance gap between the two became much smaller.

however, this sequence was much simpler. Developers could just create a command object directly, pass-ing in the connection information and executing