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如題,今天介紹 SpringBoot 與 Mybatis 的整合以及 Mybatis 的使用,以前介紹過了 SpringBoot 整合MyBatis 註解版的使用,上一篇介紹過 MyBatis 的理論,今天這篇就不介紹 MyBatis 的理論了,有興趣的跳轉閱讀:SpringBoot 實戰 (十三) | 整合 MyBatis (註解版)前端
CREATE TABLE `student` (
`id` int(32) NOT NULL AUTO_INCREMENT,
`student_id` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '學號',
`name` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '姓名',
`age` int(11) NULL DEFAULT NULL COMMENT '年齡',
`city` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '所在城市',
`dormitory` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '宿舍',
`major` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '專業',
PRIMARY KEY (`id`) USING BTREE
)ENGINE=INNODB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8;
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<dependencies>
<!-- jdbc 鏈接驅動 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!-- web 啓動類 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- mybatis 依賴 -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.0.0</version>
</dependency>
<!-- druid 數據庫鏈接池 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.14</version>
</dependency>
<!-- Mysql 鏈接類 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
<scope>runtime</scope>
</dependency>
<!-- 分頁插件 -->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.2.5</version>
</dependency>
<!-- test 依賴 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<!-- springboot maven 插件 -->
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<!-- mybatis generator 自動生成代碼插件 -->
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.2</version>
<configuration>
<configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile>
<overwrite>true</overwrite>
<verbose>true</verbose>
</configuration>
</plugin>
</plugins>
</build>
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代碼解釋很詳細了,但這裏提一嘴,mybatis generator 插件用於自動生成代碼,pagehelper 插件用於物理分頁。java
server:
port: 8080
spring:
datasource:
name: test
url: jdbc:mysql://127.0.0.1:3306/test
username: root
password: 123456
#druid相關配置
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.jdbc.Driver
filters: stat
maxActive: 20
initialSize: 1
maxWait: 60000
minIdle: 1
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: select 'x'
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
maxOpenPreparedStatements: 20
## 該配置節點爲獨立的節點,有不少同窗容易將這個配置放在spring的節點下,致使配置沒法被識別
mybatis:
mapper-locations: classpath:mapping/*.xml #注意:必定要對應mapper映射xml文件的所在路徑
type-aliases-package: com.nasus.mybatisxml.model # 注意:對應實體類的路徑
#pagehelper分頁插件
pagehelper:
helperDialect: mysql
reasonable: true
supportMethodsArguments: true
params: count=countSql
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這裏要注意,配置 pom.xml 中 generator 插件所對應的配置文件時,在 Pom.xml 加入這一句,說明 generator 插件所對應的配置文件所對應的配置文件路徑。這裏已經在 Pom 中配置了,請見上面的 Pom 配置。mysql
${basedir}/src/main/resources/generator/generatorConfig.xml
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generatorConfig.xml :git
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
<!-- 數據庫驅動:選擇你的本地硬盤上面的數據庫驅動包-->
<classPathEntry location="D:\repository\mysql\mysql-connector-java\5.1.47\mysql-connector-java-5.1.47.jar"/>
<context id="DB2Tables" targetRuntime="MyBatis3">
<commentGenerator>
<property name="suppressDate" value="true"/>
<!-- 是否去除自動生成的註釋 true:是 : false:否 -->
<property name="suppressAllComments" value="true"/>
</commentGenerator>
<!--數據庫連接URL,用戶名、密碼 -->
<jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1/test" userId="root" password="123456">
</jdbcConnection>
<javaTypeResolver>
<property name="forceBigDecimals" value="false"/>
</javaTypeResolver>
<!-- 生成模型的包名和位置-->
<javaModelGenerator targetPackage="com.nasus.mybatisxml.model" targetProject="src/main/java">
<property name="enableSubPackages" value="true"/>
<property name="trimStrings" value="true"/>
</javaModelGenerator>
<!-- 生成映射文件的包名和位置-->
<sqlMapGenerator targetPackage="mapping" targetProject="src/main/resources">
<property name="enableSubPackages" value="true"/>
</sqlMapGenerator>
<!-- 生成DAO的包名和位置-->
<javaClientGenerator type="XMLMAPPER" targetPackage="com.nasus.mybatisxml.mapper" targetProject="src/main/java">
<property name="enableSubPackages" value="true"/>
</javaClientGenerator>
<!-- 要生成的表 tableName是數據庫中的表名或視圖名 domainObjectName是實體類名-->
<table tableName="student" domainObjectName="Student" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
</context>
</generatorConfiguration>
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代碼註釋很詳細,很少說。github
第一步:選擇編輯配置web
第二步:選擇添加 Maven 配置算法
第三步:添加命令 mybatis-generator:generate -e 點擊肯定spring
第四步:運行該配置,生成代碼sql
特別注意!!!同一張表必定不要運行屢次,由於 mapper 的映射文件中會生成屢次的代碼,致使報錯,切記。如要運行屢次,請把上次生成的 mapper 映射文件代碼刪除再運行。
第五步:檢查生成結果
請參照別人寫好的遇到問題的解決方法,其中我就遇到數據庫時區不對以及只生成 Insert 方法這兩個問題。都是看如下這篇文章解決的:
Mybatis Generator自動生成代碼以及可能出現的問題
一、實體類:Student.java
package com.nasus.mybatisxml.model;
public class Student {
private Long id;
private Integer age;
private String city;
private String dormitory;
private String major;
private String name;
private Long studentId;
// 省略 get 和 set 方法
}
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二、mapper 接口:StudentMapper.java
package com.nasus.mybatisxml.mapper;
import com.nasus.mybatisxml.model.Student;
import java.util.List;
import org.apache.ibatis.annotations.Mapper;
@Mapper
public interface StudentMapper {
int deleteByPrimaryKey(Long id);
int insert(Student record);
int insertSelective(Student record);
Student selectByPrimaryKey(Long id);
// 我添加的方法,相應的要在映射文件中添加此方法
List<Student> selectStudents();
int updateByPrimaryKeySelective(Student record);
int updateByPrimaryKey(Student record);
}
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三、映射文件:StudentMapper.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.nasus.mybatisxml.mapper.StudentMapper" >
<resultMap id="BaseResultMap" type="com.nasus.mybatisxml.model.Student" >
<id column="id" property="id" jdbcType="BIGINT" />
<result column="age" property="age" jdbcType="INTEGER" />
<result column="city" property="city" jdbcType="VARCHAR" />
<result column="dormitory" property="dormitory" jdbcType="VARCHAR" />
<result column="major" property="major" jdbcType="VARCHAR" />
<result column="name" property="name" jdbcType="VARCHAR" />
<result column="student_id" property="studentId" jdbcType="BIGINT" />
</resultMap>
<sql id="Base_Column_List" >
id, age, city, dormitory, major, name, student_id
</sql>
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Long" >
select
<include refid="Base_Column_List" />
from student
where id = #{id,jdbcType=BIGINT}
</select>
<delete id="deleteByPrimaryKey" parameterType="java.lang.Long" >
delete from student
where id = #{id,jdbcType=BIGINT}
</delete>
<insert id="insert" parameterType="com.nasus.mybatisxml.model.Student" >
insert into student (id, age, city,
dormitory, major, name,
student_id)
values (#{id,jdbcType=BIGINT}, #{age,jdbcType=INTEGER}, #{city,jdbcType=VARCHAR},
#{dormitory,jdbcType=VARCHAR}, #{major,jdbcType=VARCHAR}, #{name,jdbcType=VARCHAR},
#{studentId,jdbcType=BIGINT})
</insert>
<insert id="insertSelective" parameterType="com.nasus.mybatisxml.model.Student" >
insert into student
<trim prefix="(" suffix=")" suffixOverrides="," >
<if test="id != null" >
id,
</if>
<if test="age != null" >
age,
</if>
<if test="city != null" >
city,
</if>
<if test="dormitory != null" >
dormitory,
</if>
<if test="major != null" >
major,
</if>
<if test="name != null" >
name,
</if>
<if test="studentId != null" >
student_id,
</if>
</trim>
<trim prefix="values (" suffix=")" suffixOverrides="," >
<if test="id != null" >
#{id,jdbcType=BIGINT},
</if>
<if test="age != null" >
#{age,jdbcType=INTEGER},
</if>
<if test="city != null" >
#{city,jdbcType=VARCHAR},
</if>
<if test="dormitory != null" >
#{dormitory,jdbcType=VARCHAR},
</if>
<if test="major != null" >
#{major,jdbcType=VARCHAR},
</if>
<if test="name != null" >
#{name,jdbcType=VARCHAR},
</if>
<if test="studentId != null" >
#{studentId,jdbcType=BIGINT},
</if>
</trim>
</insert>
<update id="updateByPrimaryKeySelective" parameterType="com.nasus.mybatisxml.model.Student" >
update student
<set >
<if test="age != null" >
age = #{age,jdbcType=INTEGER},
</if>
<if test="city != null" >
city = #{city,jdbcType=VARCHAR},
</if>
<if test="dormitory != null" >
dormitory = #{dormitory,jdbcType=VARCHAR},
</if>
<if test="major != null" >
major = #{major,jdbcType=VARCHAR},
</if>
<if test="name != null" >
name = #{name,jdbcType=VARCHAR},
</if>
<if test="studentId != null" >
student_id = #{studentId,jdbcType=BIGINT},
</if>
</set>
where id = #{id,jdbcType=BIGINT}
</update>
<update id="updateByPrimaryKey" parameterType="com.nasus.mybatisxml.model.Student" >
update student
set age = #{age,jdbcType=INTEGER},
city = #{city,jdbcType=VARCHAR},
dormitory = #{dormitory,jdbcType=VARCHAR},
major = #{major,jdbcType=VARCHAR},
name = #{name,jdbcType=VARCHAR},
student_id = #{studentId,jdbcType=BIGINT}
where id = #{id,jdbcType=BIGINT}
</update>
<!-- 我添加的方法 -->
<select id="selectStudents" resultMap="BaseResultMap">
SELECT
<include refid="Base_Column_List" />
from student
</select>
</mapper>
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一、接口:
public interface StudentService {
int addStudent(Student student);
Student findStudentById(Long id);
PageInfo<Student> findAllStudent(int pageNum, int pageSize);
}
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二、實現類
@Service
public class StudentServiceImpl implements StudentService{
//會報錯,不影響
@Resource
private StudentMapper studentMapper;
/** * 添加學生信息 * @param student * @return */
@Override
public int addStudent(Student student) {
return studentMapper.insert(student);
}
/** * 根據 id 查詢學生信息 * @param id * @return */
@Override
public Student findStudentById(Long id) {
return studentMapper.selectByPrimaryKey(id);
}
/** * 查詢全部學生信息並分頁 * @param pageNum * @param pageSize * @return */
@Override
public PageInfo<Student> findAllStudent(int pageNum, int pageSize) {
//將參數傳給這個方法就能夠實現物理分頁了,很是簡單。
PageHelper.startPage(pageNum, pageSize);
List<Student> studentList = studentMapper.selectStudents();
PageInfo result = new PageInfo(studentList);
return result;
}
}
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@RestController
@RequestMapping("/student")
public class StudentController {
@Autowired
private StudentService studentService;
@GetMapping("/{id}")
public Student findStidentById(@PathVariable("id") Long id){
return studentService.findStudentById(id);
}
@PostMapping("/add")
public int insertStudent(@RequestBody Student student){
return studentService.addStudent(student);
}
@GetMapping("/list")
public PageInfo<Student> findStudentList(@RequestParam(name = "pageNum", required = false, defaultValue = "1") int pageNum, @RequestParam(name = "pageSize", required = false, defaultValue = "10") int pageSize){
return studentService.findAllStudent(pageNum,pageSize);
}
}
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@SpringBootApplication
@MapperScan("com.nasus.mybatisxml.mapper") // 掃描 mapper 接口,必須加上
public class MybatisxmlApplication {
public static void main(String[] args) {
SpringApplication.run(MybatisxmlApplication.class, args);
}
}
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提一嘴,@MapperScan("com.nasus.mybatisxml.mappe") 這個註解很是的關鍵,這個對應了項目中 mapper(dao) 所對應的包路徑,必須加上,不然會致使異常。
一、插入方法:
二、根據 id 查詢方法:
三、分頁查詢方法:
https://github.com/turoDog/Demo/tree/master/springboot_mybatisxml_demo
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