Getting Startedwith pureQuery

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Getting Started with pureQuery
10.2.2.3 Test the application
Now, run hrm.inProgress.pdqInlineStyle.HumanResourcesManager. When the
application prompts you for an employee number, use 000030. When the main menu
displays, immediately select the menu option 0 to exit the application. We have not
finished implementing the other screens yet, so they will not work.
10.3 Executing SQL SELECT statements
The Data interface provides many queryXXX methods for executing SQL SELECT
statements. Choose the one you want to use based on the format in which you want to
retrieve your data and on any other parameters that you want to be able to specify.
10.3.1 Choosing the return type
Use the following questions as a guide to help you select the right return type.
What format do you want to use for each row?
• A pureQuery bean or a scalar object: queryXXX methods that have a parameter
Class returnClass store the contents of each row in an instance of
returnClass.
o If returnClass is a pureQuery bean, pureQuery creates an instance of
returnClass and sets the values of its properties according to the values
of the columns returned from the database. pureQuery uses a consistent
set of mapping rules to determine the bean property that represents each
column that is selected from the database. When pureQuery cannot find a
property that represents a column in the SQL statement, pureQuery does
not store the value of that column in the bean.
o If returnClass is not a pureQuery bean, pureQuery constructs an object of
type returnClass and attempts to store the contents of the first column
of the query result in that object.
• An object of a specific type, constructed by a
com.ibm.pdq.runtime.handlers.RowHandler object: queryXXX
methods that have a parameter RowHandler rowHandler use
rowHandler to create the object that contains each row. Chapter 13 discusses
handlers.
• A java.util.Map object: queryXXX methods that do not
have a parameter Class returnClass or a parameter
RowHandler rowHandler return the contents of each row in a
Map object, in which the keys are the column labels, and the
values are the contents of the columns.