This release added a new set of data access controls to the control set called Data Source controls.
With these controls, it is now possible to access and do data operations without even writing a single line of code.
After a record is successfully updated, the Updated event is handled by an event handler to perform a post-processing step where an e-mail message notification is sent.
event to perform additional initialization operations that are specific to your application, to validate the values of parameters, or to change the parameter values before the Sql Data Source control performs the update operation.
To access the context, provide a function that accepts a single member is a special member provided only during the execution of a default function for the purposes of deriving defaults from its existing values.
For a single statement that is executing many sets of bind parameters, the user-defined function is called for each set of parameters, and call the function, i.e.
Below illustrates a crude “sequence” that assigns an incrementing counter to a primary key column: It should be noted that for real “incrementing sequence” behavior, the built-in capabilities of the database should normally be used, which may include sequence objects or other autoincrementing capabilities.
For primary key columns, SQLAlchemy will in most cases use these capabilities automatically.
The typical use case for this context with regards to default generation is to have access to the other values being inserted or updated on the row.with parenthesis “()” - this is because what we want in this case is the return value of the function, which is the SQL expression construct that will be rendered into the INSERT or UPDATE statement. Netframework 2.0, there are lot of new features added that made the data access very easier and simpler.The connection to the underlying data source is not yet open when the event handler delegate is called.Therefore, you cannot directly cancel the Update database operation by calling the Cancel method on the Db Command object that is exposed by the Sql Data Source Command Event Args object.
Update(); ...doesn't update the value :(I still haven't figured this out.