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Web Programming




                    Notes            Now what is CORBA? “When we say CORBA, we actually mean CORBA/IIOP,” that is
                                     Common Object Request  Broker Architecture/Internet  Inter-ORB. This is a technology
                                     “meant for distributed information objects that can closely interact with each other within
                                     a managing program, which essentially consists of these objects itself.” There is lot more
                                     in this `advanced’ book for the eager beaver.

                                   14.5 Summary

                                      The connection is closed when the session ends. This is controlled by the Global.asa file.
                                      Each ASP-Based intranet application can have one global.asa file located in the root directory
                                       of the application.
                                      Databases and ASP (Communicating with a Database using ActiveX Data Objects (ADO);
                                       Connecting to a Database (The Connection Object, Using a System DSN, Using a DSN-less
                                       Connection, Opening the Connection, Closing the connection, Properties of the connection);
                                       Reading  data from  a Database  (The Recordset  Object, Using adovbs.inc, Reading  and
                                       Displaying the contents of a Database Table).
                                      Data driven sites must be capable of editing as well as addition and deletion of data.

                                      When we make a database accessible over the WEB, there are many people accessing it at
                                       once. Accessing is OK till the people are just reading, when they try to manipulate it, it
                                       may cause problems.
                                      To prevent this the first person who tries to change the record puts a “LOCK” on it (lock
                                       basically means that another person cannot edit).

                                      While the lock is on no one can change the records. As soon as the user is finished the lock
                                       is removed.
                                      The bridge between the data providers and data consumers is through data sources created
                                       using Microsoft ActiveX Data Objects (ADO), which is the primary method in Visual Basic
                                       to access data in any data source, both relational and non-relational.

                                      For backward compatibility and project maintenance, Remote Data Objects (RDO) and
                                       Data Access Objects (DAO) are still supported.

                                   14.6 Keywords

                                   ADO: ActiveX Data Objects
                                   ASP: Active Server Pages

                                   DAO: Data Access Objects
                                   RDO: Remote Data Objects

                                   14.7 Review Questions

                                   1.  Describe the actions performed by the AddNew method of the Recordset object.
                                   2.  Substantiate the arguments which AddNew can accept?
                                   3.  Why could not you use the default locking type?

                                   4.  What does CancelUpdate do? How do you delete a record?
                                   5.  Write a page that takes the titles of the links in the table and lists them in a drop-down box.
                                       The user may then click one of the titles and then a submit button, and be taken to a page



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