Mybatis-Plus BaseMapper Mybatis-Plus BaseMapper的用法详解
金色的鱼儿 人气:0想了解Mybatis-Plus BaseMapper的用法详解的相关内容吗，金色的鱼儿在本文为您仔细讲解Mybatis-Plus BaseMapper的相关知识和一些Code实例，欢迎阅读和指正，我们先划重点：Mybatis-Plus,BaseMapper，下面大家一起来学习吧。
1、如何使用BaseMapper进行数据库的操作。
2、使用BaseMapper进行插入实体时如何让UUID的主键自动生成。
Student实体类，其中id属性主键为UUID
package com.huixiaoer.ant.api.model.bean;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
public class Student {
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column student.id
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
@TableId(type= IdType.UUID)
private String id;
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column student.user_name
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
private String userName;
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column student.age
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
private Integer age;
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column student.phone
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
private String phone;
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table student
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
public Student(String id, String userName, Integer age, String phone) {
this.id = id;
this.userName = userName;
this.age = age;
this.phone = phone;
}
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table student
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
public Student() {
super();
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column student.id
*
* @return the value of student.id
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
public String getId() {
return id;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column student.id
*
* @param id the value for student.id
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
public void setId(String id) {
this.id = id == null ? null : id.trim();
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column student.user_name
*
* @return the value of student.user_name
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
public String getUserName() {
return userName;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column student.user_name
*
* @param userName the value for student.user_name
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
public void setUserName(String userName) {
this.userName = userName == null ? null : userName.trim();
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column student.age
*
* @return the value of student.age
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
public Integer getAge() {
return age;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column student.age
*
* @param age the value for student.age
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
public void setAge(Integer age) {
this.age = age;
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column student.phone
*
* @return the value of student.phone
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
public String getPhone() {
return phone;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column student.phone
*
* @param phone the value for student.phone
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
public void setPhone(String phone) {
this.phone = phone == null ? null : phone.trim();
}
}
StudnetVI实体类，用户从页面接收参数
package com.huixiaoer.ant.api.model.vi;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
@ApiModel(value = "student对象",description = "学生对象student")
public class StudentVI {
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column student.user_name
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
@ApiModelProperty(value="学生姓名",name="userName",required=true)
private String userName;
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column student.age
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
@ApiModelProperty(value="年龄",name="age",required=true)
private Integer age;
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column student.phone
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
@ApiModelProperty(value="手机号",name="phone",required=true)
private String phone;
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
}
StudentPlusMapper接口类，实现BaseMapper用来实现Mybatis-Plus的增强功能。
package com.huixiaoer.ant.api.repository.mysql.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.huixiaoer.ant.api.model.bean.Student;
public interface StudentPlusMapper extends BaseMapper<Student> {
//不需要实现，这时候就可以调用baseMapper的增删改查了
}
StudentService业务接口类
package com.huixiaoer.ant.api.service;
import com.huixiaoer.ant.api.model.bean.Student;
import com.huixiaoer.ant.api.model.bean.StudentExample;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.SelectKey;
import java.util.List;
public interface StudentService {
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table student
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
long countByExample(StudentExample example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table student
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
int deleteByExample(StudentExample example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table student
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
@Insert({
"insert into student (id, user_name, ",
"age, phone)",
"values (#{id,jdbcType=VARCHAR}, #{userName,jdbcType=VARCHAR}, ",
"#{age,jdbcType=INTEGER}, #{phone,jdbcType=VARCHAR})"
})
@SelectKey(statement="select uuid_short()", keyProperty="id", before=true, resultType=String.class)
int insert(Student record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table student
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
int insertSelective(Student record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table student
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
List<Student> selectByExample(StudentExample example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table student
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
int updateByExampleSelective(@Param("record") Student record, @Param("example") StudentExample example);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table student
*
* @mbg.generated Thu Oct 31 14:09:39 CST 2019
*/
int updateByExample(@Param("record") Student record, @Param("example") StudentExample example);
}
StudentServiceImpl业务接口实现类，这里将mybatis-plus的mapper接口注入其中。
package com.huixiaoer.ant.api.service.impl;
import com.huixiaoer.ant.api.model.bean.Student;
import com.huixiaoer.ant.api.model.bean.StudentExample;
import com.huixiaoer.ant.api.repository.mysql.mapper.StudentMapper;
import com.huixiaoer.ant.api.repository.mysql.mapper.StudentPlusMapper;
import com.huixiaoer.ant.api.service.StudentService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
@Slf4j
public class StudentServiceImpl implements StudentService {
@Autowired
private StudentMapper studentMapper;
@Autowired
private StudentPlusMapper studentPlusMapper;
@Override
public long countByExample(StudentExample example) {
return 0;
}
@Override
public int deleteByExample(StudentExample example) {
return 0;
}
@Override
public int insert(Student record) {
return studentPlusMapper.insert(record);
}
@Override
public int insertSelective(Student record) {
return studentMapper.insertSelective(record);
}
@Override
public List<Student> selectByExample(StudentExample example) {
return null;
}
@Override
public int updateByExampleSelective(Student record, StudentExample example) {
return 0;
}
@Override
public int updateByExample(Student record, StudentExample example) {
return 0;
}
}
SchoolController类，实现前端和后台的交互。自动注入学生业务实现类。
package com.huixiaoer.ant.api.controller;
import com.huixiaoer.ant.api.common.constant.ResultCode;
import com.huixiaoer.ant.api.model.bean.Student;
import com.huixiaoer.ant.api.model.vi.StudentVI;
import com.huixiaoer.ant.api.service.impl.StudentServiceImpl;
import com.huixiaoer.ant.api.util.*;
import io.swagger.annotations.*;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.UUID;
/**
* @author create by yiqiang.wu
* @create 2019/06/12
* @email yiqiang.wu@huixiaoer.com
* @description 登录
*/
@Slf4j
@RestController
@Api(tags = "学校 相关接口")
public class SchoolController {
@Autowired
private StudentServiceImpl studentService;
@Autowired
private HttpServletRequest request;
@ApiOperation(value = "增加学生信息")
@PostMapping(value = "/insert/student")
public CommonResult insertStudent(@RequestBody @ApiParam(name="学生对象",value="传入json格式",required=true) StudentVI studentVI) {
try {
Student student = new Student();
// student.setId(UUID.randomUUID().toString());
student.setUserName(studentVI.getUserName());
student.setAge(studentVI.getAge());
student.setPhone(studentVI.getPhone());
studentService.insert(student);
} catch (Exception e) {
System.out.println(e);
return CommonUtil.buildResponse(ResultCode.SYSTEM_ERROR, ResultCode.SYSTEM_ERROR_MSG);
}
return CommonUtil.buildResponse(ResultCode.SUCCESS, ResultCode.SUCCESS_MSG);
}
}
补充一下Mybatis的xml文件
<?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.huixiaoer.ant.api.repository.mysql.mapper.StudentMapper">
<resultMap id="BaseResultMap" type="com.huixiaoer.ant.api.model.bean.Student">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Oct 31 14:09:39 CST 2019.
-->
<constructor>
<arg column="id" javaType="java.lang.String" jdbcType="VARCHAR" />
<arg column="user_name" javaType="java.lang.String" jdbcType="VARCHAR" />
<arg column="age" javaType="java.lang.Integer" jdbcType="INTEGER" />
<arg column="phone" javaType="java.lang.String" jdbcType="VARCHAR" />
</constructor>
</resultMap>
<sql id="Example_Where_Clause">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Oct 31 14:09:39 CST 2019.
-->
<where>
<foreach collection="oredCriteria" item="criteria" separator="or">
<if test="criteria.valid">
<trim prefix="(" prefixOverrides="and" suffix=")">
<foreach collection="criteria.criteria" item="criterion">
<choose>
<when test="criterion.noValue">
and ${criterion.condition}
</when>
<when test="criterion.singleValue">
and ${criterion.condition} #{criterion.value}
</when>
<when test="criterion.betweenValue">
and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
</when>
<when test="criterion.listValue">
and ${criterion.condition}
<foreach close=")" collection="criterion.value" item="listItem" open="(" separator=",">
#{listItem}
</foreach>
</when>
</choose>
</foreach>
</trim>
</if>
</foreach>
</where>
</sql>
<sql id="Update_By_Example_Where_Clause">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Oct 31 14:09:39 CST 2019.
-->
<where>
<foreach collection="example.oredCriteria" item="criteria" separator="or">
<if test="criteria.valid">
<trim prefix="(" prefixOverrides="and" suffix=")">
<foreach collection="criteria.criteria" item="criterion">
<choose>
<when test="criterion.noValue">
and ${criterion.condition}
</when>
<when test="criterion.singleValue">
and ${criterion.condition} #{criterion.value}
</when>
<when test="criterion.betweenValue">
and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
</when>
<when test="criterion.listValue">
and ${criterion.condition}
<foreach close=")" collection="criterion.value" item="listItem" open="(" separator=",">
#{listItem}
</foreach>
</when>
</choose>
</foreach>
</trim>
</if>
</foreach>
</where>
</sql>
<sql id="Base_Column_List">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Oct 31 14:09:39 CST 2019.
-->
id, user_name, age, phone
</sql>
<select id="selectByExample" parameterType="com.huixiaoer.ant.api.model.bean.StudentExample" resultMap="BaseResultMap">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Oct 31 14:09:39 CST 2019.
-->
select
<if test="distinct">
distinct
</if>
<include refid="Base_Column_List" />
from student
<if test="_parameter != null">
<include refid="Example_Where_Clause" />
</if>
<if test="orderByClause != null">
order by ${orderByClause}
</if>
</select>
<delete id="deleteByExample" parameterType="com.huixiaoer.ant.api.model.bean.StudentExample">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Oct 31 14:09:39 CST 2019.
-->
delete from student
<if test="_parameter != null">
<include refid="Example_Where_Clause" />
</if>
</delete>
<insert id="insertSelective" parameterType="com.huixiaoer.ant.api.model.bean.Student">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Oct 31 14:09:39 CST 2019.
-->
<selectKey keyProperty="id" order="BEFORE" resultType="java.lang.String">
select uuid_short()
</selectKey>
insert into student
<trim prefix="(" suffix=")" suffixOverrides=",">
id,
<if test="userName != null">
user_name,
</if>
<if test="age != null">
age,
</if>
<if test="phone != null">
phone,
</if>
</trim>
<trim prefix="values (" suffix=")" suffixOverrides=",">
#{id,jdbcType=VARCHAR},
<if test="userName != null">
#{userName,jdbcType=VARCHAR},
</if>
<if test="age != null">
#{age,jdbcType=INTEGER},
</if>
<if test="phone != null">
#{phone,jdbcType=VARCHAR},
</if>
</trim>
</insert>
<select id="countByExample" parameterType="com.huixiaoer.ant.api.model.bean.StudentExample" resultType="java.lang.Long">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Oct 31 14:09:39 CST 2019.
-->
select count(*) from student
<if test="_parameter != null">
<include refid="Example_Where_Clause" />
</if>
</select>
<update id="updateByExampleSelective" parameterType="map">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Oct 31 14:09:39 CST 2019.
-->
update student
<set>
<if test="record.id != null">
id = #{record.id,jdbcType=VARCHAR},
</if>
<if test="record.userName != null">
user_name = #{record.userName,jdbcType=VARCHAR},
</if>
<if test="record.age != null">
age = #{record.age,jdbcType=INTEGER},
</if>
<if test="record.phone != null">
phone = #{record.phone,jdbcType=VARCHAR},
</if>
</set>
<if test="_parameter != null">
<include refid="Update_By_Example_Where_Clause" />
</if>
</update>
<update id="updateByExample" parameterType="map">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Thu Oct 31 14:09:39 CST 2019.
-->
update student
set id = #{record.id,jdbcType=VARCHAR},
user_name = #{record.userName,jdbcType=VARCHAR},
age = #{record.age,jdbcType=INTEGER},
phone = #{record.phone,jdbcType=VARCHAR}
<if test="_parameter != null">
<include refid="Update_By_Example_Where_Clause" />
</if>
</update>
</mapper>
各种UUID生成策略，生成的UUID值进行比较。
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