Getting Startedwith pureQuery

Chapter 9 – Persistence Frameworks and Data Access: Context for pureQuery 173
match the bean field names in the EmployeeBean above. pureQuery does the work to
map the result columns to the correct bean fields.
SELECT EMPLOYEE.EMPNO, EMPLOYEE.FIRSTNME, EMPLOYEE.LASTNAME,
DEPARTMENT.DEPTNO FROM EMPLOYEE LEFT JOIN DEPARTMENT ON EMPLOYEE.WORKDEPT
= DEPARTMENT.DEPTNO
Listing 9.2- An example SQL query to populate the EmployeeBean.
A pureQuery bean is a Java class that defines a set of properties. Each property is
defined either by a public field, or by a pair of public accessor methods. The following rules
define how pureQuery determines the properties in a bean.
• Public field: The name of the field indicates the name of the property. For example,
a field defined as public String employeeNumber would represent a property
named “employeeNumber”.
• Public accessor methods: Each property defined by accessor methods must have
one setter accessor method and one getter accessor method. Any setter method
in a pureQuery bean must have a corresponding getter method, and vice versa,
Setter and getter methods are defined according to these rules:
o
o
Setter methods: The names of setter methods start with “set”. These
methods have exactly one parameter. A setter method named
“setAbcDef” indicates a property named “abcDef.” For example, a bean
could contain a method that is defined as: public void
setEmployeeNumber(String);. Such a method would indicate a
property named “employeeBean.”
Getter methods: The names of getter methods start with “get” or “is”.
These methods have no parameters. A getter method named “getAbcDef”
indicates a property named “abcDef,” as does a getter method named
“isAbcDef” when property “abcDef” is of Boolean type. For example, a
bean could contain a method that is defined as: public String
getEmployeeNumber();. Such a method would indicate a property
named “employeeNumber.”
The names of the properties in a pureQuery bean must be unique in a case-insensitive
search. Therefore, for example, if you have a pair of public accessor methods named
setEmployeeNumber and getEmployeeNumber, you could not also have a pair of
public accessor methods named setEmployeenumber and getEmployeenumber. You
also could not have a public field named employeenumber.
Every pureQuery bean must have a no-argument constructor, either explicit or implicit.
Additionally, the type of each property must be supported by JDBC.
By default, pureQuery maps a pureQuery bean property to a database column with the
same name or alias. You can use Java annotations to change these mappings. The
annotations are as follows:
• @Column