mybatis 插入数据并返回主键值

<insert id="insert" parameterType="com.pojo.TSubject" useGeneratedKeys="true"  keyProperty="subjectid" > 
insert into t_subject ( parentid, subjectname, subjecttype, subjectitem, subjectanser, displaytype) values ( #{parentid,jdbcType=INTEGER}, #{subjectname,jdbcType=VARCHAR}, #{subjecttype,jdbcType=VARCHAR}, #{subjectitem,jdbcType=VARCHAR}, #{subjectanser,jdbcType=VARCHAR}, #{displaytype,jdbcType=VARCHAR}) 

</insert>

useGeneratedKeys="true"  keyProperty="subjectid"
“subjectid”表主键

subjectService.insert(tSubject);
插入成功后：tSubject..getSubjectid() 就可以得到刚刚插入记录主键id