Getting Startedwith pureQuery

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Getting Started with pureQuery
We are executing a SELECT statement, so we use the
com.ibm.pdq.annotation.Select annotation. Since we need several pieces of
information about each employee, it would be convenient to retrieve each row as an
instance of EmployeeBean. We will be selecting all the employees in the database, but
we would prefer not to have to store all of the company's employees in the application’s
memory at once, since that could be quite a lot of memory, so we will return the rows in a
java.util.Iterator object. Therefore, we will use
java.util.Iterator as the return type of our method.
Our SQL statement does not have any parameters, so the method does not need any
parameters.
While users are viewing the list of employees, they can request to view additional
information about an employee and then return to the list. Therefore, we need to set the
cursor holdability to “hold cursors over commit.” We use the
com.ibm.pdq.annotation.Cursor annotation to specify the holdability cursor attribute
java.sql.ResultSet.HOLD_CURSORS_OVER_COMMIT. Listing 11.9 shows the
definition of the new annotated method.
@Cursor(holdability = ResultSet.HOLD_CURSORS_OVER_COMMIT)
@Select(sql = "SELECT * FROM EMPLOYEE ORDER BY LASTNAME, FIRSTNME,
MIDINIT")
Iterator selectAllEmployees ();
Listing 11.9 - Add an annotated method to the HumanResourcesData interface that
creates an Iterator of all the employees
After you have added the method to
hrm.inProgress.pdqMethodStyle.HumanResourcesData, build your project so that
Optim Development Studio will generate an implementation class. Confirm that
hrm.inProgress.pdqMethodStyle.HumanResourcesDataImpl was generated
without any problems. Figure 11.6 shows the location of the new file. If IBM Optim
Development studio has placed a red exception marker on the interface, read the text of
the exception and determine what you need to do to solve the problem.
Figure 11.6 - The generated implementation class HumanResourcesDataImpl
11.4.2.2 Modify the displayAllEmployees method to use the new annotated
method
In hrm.inProgress.pdqMethodStyle.HumanResourcesManager, modify the
displayAllEmployees method to use the new annotated method to query the database