Mybatis查询语句结果集的总结大全

<!--建表语句：-->
create table TEST.STUDENT
(
 SNO varchar(3) not null,
 SNAME varchar(4) not null,
 SSEX varchar(2) not null,
 SBIRTHDAY datetime null,
 CLASS varchar(5) null
)

<!--Bean 文件-->
public class Student {
 private String SNO;
 private String SNAME;
 private String SSEX;
 private Date SBIRTHDAY;
 private String CLASS;
 
 <!--get 和 set 方法-->
 ...
}

<!--单条结果集-->
String querySingleStudent();
<!--多条结果集-->
List<String> queryAllStudent();

<!--单条结果集-->
<select id="querySingleStudent" resultType="string">
 SELECT SNAME FROM TEST.STUDENT LIMIT 1
</select>
<!--多条结果集-->
<select id="queryAllStudent" resultType="string">
 SELECT SNAME FROM TEST.STUDENT
</select>

<!--单条结果集-->
Map<String, Object> queryStudentMap();
<!--多条结果集-->
List<Map<String, Object>> queryAllStudentMap();
复制代码Mapper 文件:
<!--单条结果集-->
<select id="queryStudentMap" resultType="hashmap">
 SELECT SNAME FROM TEST.STUDENT LIMIT 1
</select>
<!--多条结果集-->
<select id="queryAllStudentMap" resultType="hashmap">
 SELECT SNAME FROM TEST.STUDENT
</select>

<!--单条结果集-->
Student querySingleStudentBean();
<!--多条结果集-->
List<Student> queryAllStudentBean();

<!--单条结果集-->
<select id="queryStudentMap" resultType="student">
 SELECT SNAME FROM TEST.STUDENT LIMIT 1
</select>
<!--多条结果集-->
<select id="queryAllStudentMap" resultType="student">
 SELECT SNAME FROM TEST.STUDENT
</select>

<typeAliases>
 <typeAlias type="com.bean.Student" alias="student"/>
 ...
</typeAliases>

<typeAliases>
 <package name="包名"/>
</typeAliases>

<resultMap id="resultMapDemo" type="" autoMapping="true">
 <result property="" column="" jdbcType="VARCHAR" />
</resultMap>

<select id="demoID" resultMap="resultMapDemo">
...
<select>

<!--建表语句-->
create table SCORE
(
 SNO varchar(3) not null,
 CNO varchar(5) not null,
 DEGREE decimal(10, 1) not null
)

<!--Bean 文件-->
public class Score {
 private String SNO;
 private String CNO;
 private Double DEGREE;
 <!--get 和 set 方法-->
 ...
}

<!--Student.java-->
private Score score;
public Score getScore() {
 return score;
}
public void setScore(Score score) {
 this.score = score;
}

<resultMap id="allstudentResultMap" type="student">
 <!--指定第二个 SELECT 语句,和传递的字段-->
 <association property="score" column="sno" select="queryScore" />
</resultMap>

<!--第一个 SQL -->
<select id="queryAllStudent" resultMap="allstudentResultMap">
 select SNO,SNAME
 from test.STUDENT
</select>

<!--第二个 SQL-->
<select id="queryScore" resultType="score">
 select degree from test.SCORE
 where sno = #{sno}
</select>

<!--mybatis-config.xml-->
<setting name="lazyLoadingEnabled" value="true"/>
<setting name="aggressiveLazyLoading" value="false"/>

<!--嵌套结果-->
<resultMap id="associationDemoMap" type="student" autoMapping="true">
 <association property="score" javaType="score">
  <result property="SNO" column="SC_SNO"/>
 </association>
</resultMap>

<select id="queryStudentScore" resultMap="associationDemoMap">
 SELECT SNAME, SSEX, CLASS, ST.SNO, SC.SNO AS SC_SNO
 FROM test.student st INNER JOIN test.score sc 
 ON st.sno = sc.sno
 where CNO = '3-105';
</select>

<resultMap id="associationDemoMap" type="student" autoMapping="true">
 <!--columnPrefix 指定别名的前缀-->
 <association property="score" resultMap="anotherMap" columnPrefix="SC_" />
</resultMap>

<!--方便重用-->
<resultMap id="anotherMap" type="score" autoMapping="true">
</resultMap>

<!--Student.java-->
private List<Score> score;
public List<Score> getScore() {
 return score;
}
public void setScore(List<Score> score) {
 this.score = score;
}

<resultMap id="collectionDemoMap" type="student" autoMapping="true">
 <!--多出了 ofType 属性-->
 <collection property="score" ofType="score">
  <result property="SNO" column="SC_SNO"/>
 </collection>
</resultMap>

<select id="queryStudentScore" resultMap="collectionDemoMap">
 SELECT SNAME,SSEX,CLASS,ST.SNO,SC.SNO AS SC_SNO
 FROM test.student st INNER JOIN test.score sc
 ON st.sno = sc.sno
</select>