This is usually true of management or workflow-oriented systems.Since pessimistic locking anticipates contention for the same record, we take precautions by preventing users from selecting a record for editing when another user has already done so, thereby locking the record.When he gets to customer XYZ, he retrieves the record to edit it but he is distracted by a lengthy phone call.
As an example, you have the following types of connection objects in ADO. While the former is a bridge between the Data Set and the underlying database, the later is an in-memory representation of data.
NET: Note that the Execute Non Query method returns an integer representing the number of rows affected in the operation. The most important methods of the Data Adapter class are: The Fill method is used to populate a Data Set instance with data from the database.
Today's enterprise applications have one thing in common, multiple users accessing the system at the same time.
In this type of scenario, you are bound to have users attempting to edit the same data at the same time, especially when there is a single data source associated with the application.
This competition for data is known as a concurrency condition and can result in a lack of integrity in your database or worse, a loss of data. He is currently working on updating the payment terms associated with each of the customer accounts in the Widget Store Customer Database.