# 16.4\. 定制裝載SQL 你可能需要聲明你自己的SQL(或HQL)來裝載實體 ``` <sql-query name="person"> <return alias="pers" class="Person" lock-mode="upgrade"/> SELECT NAME AS {pers.name}, ID AS {pers.id} FROM PERSON WHERE ID=? FOR UPDATE </sql-query> ``` 這只是一個前面討論過的命名查詢聲明，你可以在類映射里引用這個命名查詢。 ``` <class name="Person"> <id name="id"> <generator class="increment"/> </id> <property name="name" not-null="true"/> <loader query-ref="person"/> </class> ``` 這也可以用于存儲過程 你甚至可以定一個用于集合裝載的查詢: ``` <set name="employments" inverse="true"> <key/> <one-to-many class="Employment"/> <loader query-ref="employments"/> </set> ``` ``` <sql-query name="employments"> <load-collection alias="emp" role="Person.employments"/> SELECT {emp.*} FROM EMPLOYMENT emp WHERE EMPLOYER = :id ORDER BY STARTDATE ASC, EMPLOYEE ASC </sql-query> ``` 你甚至還可以定義一個實體裝載器，它通過連接抓取裝載一個集合: ``` <sql-query name="person"> <return alias="pers" class="Person"/> <return-join alias="emp" property="pers.employments"/> SELECT NAME AS {pers.*}, {emp.*} FROM PERSON pers LEFT OUTER JOIN EMPLOYMENT emp ON pers.ID = emp.PERSON_ID WHERE ID=? </sql-query> ```