SpringBoot 2.1.6 集成 Mybatis

SpringBoot 2.1.6 集成 Mybatis

使用SpringBoot集成 Mybatis有兩種方式，本文使用IDEA搭建：

• 1.Spring Initializr
• 2.使用IDEA插件

環境信息：
OS：Win10
Jdk：JavaSE 8
Ide：Idea Ultimate
MySQL：8.0.16
MyBatis：3.5.2
Spring Boot：2.1.6.RELEASE

2.創建Web項目

Idea集成了Spring Initializr，新建項目：

• 1.選擇Spring Initializr，新建項目並填寫基本信息
  

• 3.選擇需要的工具
  選擇Web、MySQL Driver和MyBatis Framework等必要依賴：

• 4.確認完成，進行下一步。

4.集成Mybatis

4.1 創建Domain

Student:

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class Student {
    private Integer id;
    private String name;
    private Integer age;
    private String sex;
    private String hobbies;
    private String address;
}

Score:

@Data
@Builder
public class Score {

    private Integer id;
    //學生編號
    private Integer studentId;

    private String studentName;
    //科目
    private String subject;
    //科目成績
    private Integer subjectScore;
}

StudentScore:

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class StudentScore {
    private String name;
    private Integer age;
    private String sex;
    private Score score;
}

StudentScores:

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class StudentScores {
    private String name;
    private Integer age;
    private String sex;
    private List<Score> scoreList;
}

4.2 配置文件

application.properties：

spring.application.name=student-service
spring.boot.admin.client.enabled=true
spring.profiles.active=dev

配置MySQL連接，MyBatis掃描包路徑等配置信息：
application-dev.yml：

server:
  connection-timeout: 30000ms
  port: 8081
  servlet.context-path: /

logging:
  path: ./
  file: st.log
  #max-size: 10M
  #max-history: 1
  level:
    root: INFO
    org:
      springframework:
        web: INFO
    com:
      wxx:
        sbmm:
          mapper: DEBUG

spring:
  data:
  datasource:
    # 遇到時區問題用這個
    # jdbc:mysql://localhost:3306?useUnicode=true&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    url: jdbc:mysql://localhost:3306/studentService?useSSL=false&useUnicode=true&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 12345678
    # schema.sql中一般存放的是DDL腳本，即通常爲創建或更新庫表的腳本
    # data.sql中一般是DML腳本，即通常爲數據插入腳本
    schema: classpath:schema.sql
    data: classpath:data.sql
    platform: mysql
    initialization-mode: always
    continue-on-error: false
    #data-password:
    #data-username:
    #schema-password:
    #schema-username:
    sql-script-encoding: utf-8
    separator: ;
    # type: com.alibaba.druid.pool.DruidDataSource

更多MyBatis配置可參考[Configuration部分]：http://www.mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/index.html

4.3 配置數據庫初始化腳本

schema.sql：初始化建表SQL

CREATE DATABASE IF NOT EXISTS `studentService`;

CREATE TABLE IF NOT EXISTS `t_student` (
`id` INT NOT NULL AUTO_INCREMENT COMMENT 'ID',
`name` VARCHAR(255)  DEFAULT "" COMMENT '姓名',
`age` INT DEFAULT 10 COMMENT '年齡',
`sex` VARCHAR(255)DEFAULT "Male" COMMENT '性別',
`hobbies` VARCHAR(255) DEFAULT "" COMMENT '愛好',
`address` VARCHAR(255) DEFAULT "" COMMENT '住址',
PRIMARY KEY(`id`),
UNIQUE INDEX  `idx_student_name_address` (`name`,`address`) USING BTREE
)ENGINE = INNODB DEFAULT CHARSET=utf8 AUTO_INCREMENT = 1  COMMENT '學生表';

CREATE TABLE IF NOT EXISTS `t_score` (
  `id` INT NOT NULL AUTO_INCREMENT COMMENT 'ID',
`student_id` INT DEFAULT 0 COMMENT '學生ID',
`student_name` VARCHAR(255) DEFAULT "" COMMENT '學生姓名',
`subject` VARCHAR(255) DEFAULT "" COMMENT '學科',
`subject_score` INT COMMENT '學科成績',
PRIMARY KEY(`id`),
UNIQUE INDEX  `idx_score_studentname_subject` (`student_name`,`subject`) USING BTREE ,
FOREIGN KEY (student_name) REFERENCES t_student (name)
)ENGINE = INNODB DEFAULT CHARSET=utf8 AUTO_INCREMENT = 1  COMMENT '學生成績表';

data.sql：初始化數據SQL

INSERT INTO t_student (name,age, sex, hobbies,  address)
  SELECT "Even",9,"Male","ShuXue,English","XiAn" FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_student WHERE name = "Even");
INSERT INTO t_student (name,age, sex, hobbies,  address)
  SELECT "Weison",11,"Male","XuWen,WuLi","HeNan" FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_student WHERE name = "Weison");
INSERT INTO t_student (name,age, sex, hobbies,  address)
  SELECT "Angule",13,"Female","XuWen,English","Chengdu" FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_student WHERE name = "Angule");



INSERT INTO t_score (student_id,student_name, subject,  subject_score)
  SELECT 1,"Even","YuWen",90 FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_score WHERE student_name = "Even" and subject ="YuWen");

INSERT INTO t_score (student_id,student_name, subject,  subject_score)
  SELECT 1,"Even","ShuXue",89 FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_score WHERE student_name = "Even" and subject ="ShuXue");

INSERT INTO t_score (student_id,student_name, subject,  subject_score)
  SELECT 1,"Even","English",67 FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_score WHERE student_name = "Even" and subject ="English");

INSERT INTO t_score (student_id,student_name, subject,  subject_score)
  SELECT 2,"Weison","YuWen",69 FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_score WHERE student_name = "Weison" and subject ="YuWen");
INSERT INTO t_score (student_id,student_name, subject,  subject_score)
  SELECT 2,"Weison","ShuXue",94 FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_score WHERE student_name = "Weison" and subject ="ShuXue");
INSERT INTO t_score (student_id,student_name, subject,  subject_score)
  SELECT 2,"Weison","English",82 FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_score WHERE student_name = "Weison" and subject ="English");


INSERT INTO t_score (student_id,student_name, subject,  subject_score)
  SELECT 3,"Angule","YuWen",58 FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_score WHERE student_name = "Angule" and subject ="YuWen");
INSERT INTO t_score (student_id,student_name, subject,  subject_score)
  SELECT 3,"Angule","ShuXue",73 FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_score WHERE student_name = "Angule" and subject ="ShuXue");
INSERT INTO t_score (student_id,student_name, subject,  subject_score)
  SELECT 3,"Angule","English",91 FROM DUAL WHERE NOT EXISTS(SELECT 1 FROM t_score WHERE student_name = "Angule" and subject ="English");

commit;

4.4 配置SQL XML

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.wxx.sbmm.mapper.StudentMapper">

    <!--
    執行增加操作的SQL語句
    1.id和parameterType 分別與StudentMapper接口中的addStudent方法的名字和 參數類型一致
    2.以#{studentName}的形式引用Student參數 的studentName屬性，MyBatis將使用反射讀取Student參數的此屬性
    3.#{studentName}中studentName大小寫敏感。引用其他的屬性與此一致
    4.seGeneratedKeys設置爲"true"表明要MyBatis獲取由數據庫自動生成的主鍵
    5.keyProperty="id"指定把獲取到的主鍵值注入到Student的id屬性
    -->


    <!-- 當表中字段名跟實體類字段名不一致 或 爲了返回list類型 可以定義returnMap -->
    <resultMap id="studentMap" type="Student">
        <id column="id" property="id"/>
        <result column="name" property="name"/>
        <result column="age" property="age"/>
        <result column="sex" property="sex"/>
        <result column="hobbies" property="hobbies"/>
        <result column="address" property="address"/>
    </resultMap>

    <resultMap id="scoreResultMap" type="Score">
        <id column="id" property="id"/>
        <result column="student_id" property="studentId"/>
        <result column="student_name" property="studentName"/>
        <result column="subject" property="subject"/>
        <result column="subject_score" property="subjectScore"/>
    </resultMap>


    <!--增刪改查 開始-->
    <!--新增 1-->
    <insert id="saveStudent" parameterType="Student" useGeneratedKeys="true" keyProperty="id">
        insert into t_student(name,age,sex,hobbies,address)
        values(#{name},#{age},#{sex},#{hobbies},#{address})
    </insert>

    <!--刪除 1-->
    <delete id="deleteStudentByName" parameterType="String">
        delete from t_student where name=#{name}
    </delete>
    <!--刪除 2-->
    <delete id="deleteByStudent" parameterType="com.wxx.sbmm.domain.Student">
        delete from t_student where name=#{name}
    </delete>

    <!--修改 1-->
    <update id="updateStudent" parameterType="com.wxx.sbmm.domain.Student">
        update t_student set
        age = #{age},
        sex = #{sex},
        hobbies = #{hobbies},
        address = #{address},
        where name=#{name}
    </update>

    <!--查詢 1  -->
    <select id="findStudentByName" parameterType="String" resultMap="studentMap">
        SELECT * FROM t_student where name = #{name};
    </select>

    <!--查詢 2 返回list的select語句，注意resultMap的值是指向前面定義好的 -->
    <select id="findStudents" resultMap="studentMap">
        select * from t_student
    </select>

    <!--查詢 3 利用 hashMap 傳遞多個參數 -->
    <select id="findStudentByMap" parameterType="map" resultType="com.wxx.sbmm.domain.Student">
        select * from t_student where
        <where>
            1=1
            <if test="name != null and name != ''">
                and name = #{name}
            </if>
            <if test="age != null and age != ''">
                and age = #{age}
            </if>
            <if test="sex != null and sex != ''">
                and sex=#{sex}
            </if>
            <if test="hobbies != null and hobbies != ''">
                and hobbies=#{hobbies}
            </if>
            <if test="address != null and address != ''">
                and address=#{address}
            </if>
        </where>
    </select>

    <!--查詢 4 利用 hashMap 傳遞多個參數 -->
    <select id="findStudentByStudent" parameterType="Student" resultType="com.wxx.sbmm.domain.Student">
        select * from t_student where
        <where>
            1=1
            <if test="name != null and name != ''">
                and name = #{name}
            </if>
            <if test="age != null and age != ''">
                and age = #{age}
            </if>
            <if test="sex != null and sex != ''">
                and sex=#{sex}
            </if>
            <if test="hobbies != null and hobbies != ''">
                and hobbies=#{hobbies}
            </if>
            <if test="address != null and address != ''">
                and address=#{address}
            </if>
        </where>
    </select>

    <!--查詢 5 Mybatis 自帶的多個參數傳遞方法 這個時候沒有 parameterType, 但用到了類似 #{param1} 類似的參數 -->
    <select id="findStudentByAgeAndSex" resultType="com.wxx.sbmm.domain.Student">
        select * from t_student where age = #{param1} and sex=#{param2}
    </select>


    <!--增刪改查 結束-->

    <!--聯合查詢 開始-->


    <!--聯合查詢:
    引入 association 看定義如下 這樣配置之後，就可以了，將select語句與resultMap對應的映射結合起來看。
    用 association 來 得到關聯的用戶，這是多對一的情況。
    -->
    <resultMap id="studentScoresResultMap" type="StudentScores">
        <result column="name" property="name"/>
        <result column="age" property="age"/>
        <result column="sex" property="sex"/>
        <association property="scoreList" javaType="List">
            <id column="id" property="id"/>
            <result column="student_id" property="studentId"/>
            <result column="student_name" property="studentName"/>
            <result column="subject_core" property="subjectScore"/>
        </association>
    </resultMap>

    <!--
    複用我們前面已經定義好的resultMap 將association 中對應的映射獨立抽取出來，可以達到複用的目的
    -->
    <resultMap id="studentScoresAssociationResultMap" type="com.wxx.sbmm.domain.StudentScores">
        <result column="name" property="name"/>
        <result column="age" property="age"/>
        <result column="sex" property="sex"/>
        <association property="scores" javaType="List" resultMap="scoreResultMap"/>
    </resultMap>

    <!-- 聯合查詢 1 -->

    <select id="findStudentScores" resultMap="studentScoresResultMap">
        select a.name,a.age,a.sex,b.id,b.student_id,b.student_name,b.subject,b.subject_score
        from t_student a,t_score b
        where
        a.name=b.name
    </select>
    <!-- 聯合查詢 2 -->

    <select id="findStudentScore" resultMap="studentScoresResultMap">
        select a.name,a.age,a.sex,b.id,b.student_id,b.student_name,b.subject,b.subject_score
        from t_student a,t_score b
        where
        a.name=b.name
        and b.subject = 'English'
    </select>

    <!-- 聯合查詢 結束 -->

</mapper>

5.代碼

5.1 創建StudentMapper

使用@Mapper 註解標明 Mapper接口，MyBatis會幫我們去實現這個接口，該接口中方法與xml中sql標籤ID相對應：

package com.wxx.sbmm.mapper;


import com.wxx.sbmm.domain.Student;
import com.wxx.sbmm.domain.StudentScore;
import com.wxx.sbmm.domain.StudentScores;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

import java.util.List;
import java.util.Map;

@Mapper
public interface StudentMapper {

    // 增刪改查
    Student saveStudent(Student student);

    Integer deleteStudentByName(@Param("name") String name);

    Integer deleteByStudent(Student student);

    Student updateStudent(Student student);

    // 5種查詢
    Student findStudentByName(@Param("name") String name);

    List<Student> findStudents();

    List<Student> findStudentByMap(Map<String, String> map);

    List<Student> findStudentByStudent(Student student);

    List<Student> findStudentByAgeAndSex(Integer age, String sex);

    // 關聯查詢
    List<StudentScores> findStudentScores();

    List<StudentScore> findStudentScore();


}

關於Mapper更多信息可參考：http://www.mybatis.org/spring/mappers.html#

5.2 創建Service

package com.wxx.sbmm.service;

import com.wxx.sbmm.domain.Student;
import com.wxx.sbmm.domain.StudentScore;
import com.wxx.sbmm.domain.StudentScores;
import com.wxx.sbmm.mapper.StudentMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Map;

@Service
public class StudentService {

    @Autowired
    private StudentMapper studentMapper;


    public Student addStudent(Student student) {
        return studentMapper.saveStudent(student);
    }

    public Integer deleteStudentByName(String name) {
        return studentMapper.deleteStudentByName(name);
    }

    public Integer deleteByStudent(Student student) {
        return studentMapper.deleteByStudent(student);
    }

    public Student updateStudent(Student student) {
        return studentMapper.updateStudent(student);
    }


    public Student findStudentByName(String name) {
        return studentMapper.findStudentByName(name);
    }

    public List<Student> findStudents() {
        return studentMapper.findStudents();
    }

    public List<Student> findStudentByMap(Map<String, String> map) {
        return studentMapper.findStudentByMap(map);
    }

    public List<Student> findStudentByStudent(Student student) {
        return studentMapper.findStudentByStudent(student);
    }


    public List<Student> findStudentByAgeAndSex(Integer age, String sex) {
        return studentMapper.findStudentByAgeAndSex(age, sex);
    }

    public List<StudentScores> findStudentScores() {
        return studentMapper.findStudentScores();
    }

    public List<StudentScore> findStudentScore() {
        return studentMapper.findStudentScore();
    }


}

5.3 創建Controller

package com.wxx.sbmm.controller;

import com.wxx.sbmm.domain.Student;
import com.wxx.sbmm.domain.StudentScore;
import com.wxx.sbmm.domain.StudentScores;
import com.wxx.sbmm.service.StudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

@RestController
public class StudentController {
    @Autowired
    private StudentService studentService;

    @PostMapping("/students")
    public Student saveStudent(@RequestBody Student student) {
        Student addStudent = studentService.addStudent(student);
        return addStudent;
    }

    @DeleteMapping("/students/{name}")
    public Integer deleteStudentByName(@PathVariable String name) {
        Integer deleteNum = studentService.deleteStudentByName(name);
        return deleteNum;
    }

    @DeleteMapping("/students")
    public Integer deleteStudentByStudent(@RequestBody Student student) {
        Integer deleteNum = studentService.deleteByStudent(student);
        return deleteNum;
    }

    @PutMapping("/students")
    public Student updateStudent(@RequestBody Student student) {
        Student updateStudent = studentService.updateStudent(student);
        return updateStudent;
    }

    @GetMapping("/students/{name}")
    public Student findStudentByName(@PathVariable String name) {
        Student student = studentService.findStudentByName(name);
        return student;
    }

    @GetMapping("/students")
    public List<Student> getStudentListByAgeAndSexAndHobbies() {
        List<Student> studentList = studentService.findStudents();
        return studentList;
    }

    @GetMapping("/students/map")
    public List<Student> findStudentByMap() {
        Map<String, String> map = new HashMap<>();
        map.put("name", "Evwn");
        List<Student> studentList = studentService.findStudentByMap(map);
        return studentList;
    }

    @GetMapping("/students/st")
    public List<Student> findStudentByStudent() {
        List<Student> studentList = studentService.findStudentByStudent(Student.builder().build());
        return studentList;
    }

    @GetMapping("/students/{age}/{sex}")
    public List<Student> findStudentByAgeAndSex(@PathVariable Integer age, @PathVariable String sex) {
        List<Student> studentList = studentService.findStudentByAgeAndSex(age, sex);
        return studentList;
    }

    @GetMapping("/students/scores")
    public List<StudentScores> findStudentScores() {
        List<StudentScores> studentList = studentService.findStudentScores();
        return studentList;
    }

    @GetMapping("/students/score")
    public List<StudentScore> findStudentScore() {
        List<StudentScore> studentScores = studentService.findStudentScore();
        return studentScores;
    }

}

5.4 最終項目

應該是這個樣子：

6. 測試

兩個比較複雜的接口返回：
/students/scores：

/students/score：

代碼 --> 鏈接