<select id="selectAllDept" parameterType="com.ladybird.hkd.model.pojo.Faculty" resultMap="department_faculty_map">
SELECT
d.dept_num,
d.dept_name,
d.tip,
f.fac_num
FROM department d
LEFT JOIN faculty f
ON d.faculty = #{fac_num}
</select>
成功
注:resultMap中的标簽傳回的是對象,如果隻想取faculty中被關聯的主鍵怎麼辦
(2)隻取表中的一列資料
public class Department {
private String dept_num;
private String dept_name;
private String faculty;
private String tip;
<select id="selectAllDept" parameterType="com.ladybird.hkd.model.pojo.Faculty" resultType="com.ladybird.hkd.model.pojo.Department">
SELECT
d.dept_num,
d.dept_name,
d.tip,
f.fac_num
FROM department d
LEFT JOIN faculty f
ON d.faculty = #{fac_num}
</select>