Hibernate —— HQL、QBC检索方式

一、HQL 检索方式

以双向的一对多来测试 HQL 检索方式。以 Department 和 Employee 为例。

建表语句：

CREATE TABLE department
(
    dept_id INT(11) PRIMARY KEY NOT NULL AUTO_INCREMENT,
    dept_name VARCHAR(50)
);
CREATE INDEX FK_8hf3vewo7w3v9doungcc51wwy ON department (dept_id);

CREATE TABLE employee
(
    emp_id INT(11) PRIMARY KEY NOT NULL AUTO_INCREMENT,
    emp_name VARCHAR(50),
    salary FLOAT,
    dept_id_fk INT(11),
    CONSTRAINT FK_miun1wlqp4ujpsgfshyfi7g9j FOREIGN KEY (dept_id_fk) REFERENCES department (dept_id)
);
CREATE INDEX FK_miun1wlqp4ujpsgfshyfi7g9j ON employee (dept_id_fk);

对应的实体和 hbm 文件

public class Department {
    private Integer deptId;
    private String deptName;
    private Set<Employee> emps = new HashSet<>();
}    

public class Employee {
    private Integer empId;
    private String empName;
    private Float salary;
    private Department dept;
}

<hibernate-mapping>
    <class name="com.solverpeng.hql.Department" table="department" schema="hibernate">
        <id name="deptId" column="dept_id">
            <generator class="native"/>
        </id>
        <property name="deptName" column="dept_name"/>
        <set name="emps" inverse="true">
            <key>
                <column name="dept_id_fk"/>
            </key>
            <one-to-many not-found="ignore" class="com.solverpeng.hql.Employee"/>
        </set>
    </class>
</hibernate-mapping>

Department.hbm.xml