# 16.2\. 命名SQL查詢 可以在映射文檔中定義查詢的名字,然后就可以象調用一個命名的HQL查詢一樣直接調用命名SQL查詢.在這種情況下,我們_不_ 需要調用`addEntity()`方法. ``` <sql-query name="persons"> <return alias="person" class="eg.Person"/> SELECT person.NAME AS {person.name}, person.AGE AS {person.age}, person.SEX AS {person.sex} FROM PERSON person WHERE person.NAME LIKE :namePattern </sql-query> ``` ``` List people = sess.getNamedQuery("persons") .setString("namePattern", namePattern) .setMaxResults(50) .list(); ``` `&lt;return-join&gt;`和 `&lt;load-collection&gt;` 元素是用來連接關聯以及將查詢定義為預先初始化各個集合的。 ``` <sql-query name="personsWith"> <return alias="person" class="eg.Person"/> <return-join alias="address" property="person.mailingAddress"/> SELECT person.NAME AS {person.name}, person.AGE AS {person.age}, person.SEX AS {person.sex}, adddress.STREET AS {address.street}, adddress.CITY AS {address.city}, adddress.STATE AS {address.state}, adddress.ZIP AS {address.zip} FROM PERSON person JOIN ADDRESS adddress ON person.ID = address.PERSON_ID AND address.TYPE='MAILING' WHERE person.NAME LIKE :namePattern </sql-query> ``` 一個命名查詢可能會返回一個標量值.你必須使用`&lt;return-scalar&gt;`元素來指定字段的別名和 Hibernate類型 ``` <sql-query name="mySqlQuery"> <return-scalar column="name" type="string"/> <return-scalar column="age" type="long"/> SELECT p.NAME AS name, p.AGE AS age, FROM PERSON p WHERE p.NAME LIKE 'Hiber%' </sql-query> ``` 你可以把結果集映射的信息放在外部的`&lt;resultset&gt;`元素中，這樣就可以在多個命名查詢間，或者通過`setResultSetMapping()`API來訪問。(此處原文即存疑。原文為：You can externalize the resultset mapping informations in a `&lt;resultset&gt;` element to either reuse them accross several named queries or through the `setResultSetMapping()` API.) ``` <resultset name="personAddress"> <return alias="person" class="eg.Person"/> <return-join alias="address" property="person.mailingAddress"/> </resultset> <sql-query name="personsWith" resultset-ref="personAddress"> SELECT person.NAME AS {person.name}, person.AGE AS {person.age}, person.SEX AS {person.sex}, adddress.STREET AS {address.street}, adddress.CITY AS {address.city}, adddress.STATE AS {address.state}, adddress.ZIP AS {address.zip} FROM PERSON person JOIN ADDRESS adddress ON person.ID = address.PERSON_ID AND address.TYPE='MAILING' WHERE person.NAME LIKE :namePattern </sql-query> ``` 另外,你可以在java代碼中直接使用hbm文件中的結果集定義信息。 ``` List cats = sess.createSQLQuery( "select {cat.*}, {kitten.*} from cats cat, cats kitten where kitten.mother = cat.id" ) .setResultSetMapping("catAndKitten") .list(); ```