1、如何使用BaseMapper進行資料庫的操作。

2、使用BaseMapper進行插入實體時如何讓UUID的主鍵自動生成。

Student實體類，其中id屬性主鍵為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實體類，使用者從頁面接收引數

package com.huixiaoer.ant.api.model.vi;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;

@ApiModel(value = "student物件",description = "學生物件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="學生姓名",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="年齡",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="手機號",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介面類，實現BaseMapper用來實現Mybatis-Plus的增強功能。

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> {
  //不需要實現，這時候就可以呼叫baseMapper的增刪改查了
}

StudentService業務介面類

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,"#{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業務介面實現類，這裡將mybatis-plus的mapper介面注入其中。

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類，實現前端和後臺的互動。自動注入學生業務實現類。

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 [email protected]
 * @description 登入
 */
@Slf4j
@RestController
@Api(tags = "學校 相關介面")
public class SchoolController {

  @Autowired
  private StudentServiceImpl studentService;

  @Autowired
  private HttpServletRequest request;

  @ApiOperation(value = "增加學生資訊")
  @PostMapping(value = "/insert/student")
  public CommonResult insertStudent(@RequestBody @ApiParam(name="學生物件",value="傳入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);
  }

}

補充一下Mybatis的xml檔案

<?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,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,<if test="userName != null">
    #{userName,</if>
   <if test="age != null">
    #{age,</if>
   <if test="phone != null">
    #{phone,</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,</if>
   <if test="record.userName != null">
    user_name = #{record.userName,</if>
   <if test="record.age != null">
    age = #{record.age,</if>
   <if test="record.phone != null">
    phone = #{record.phone,</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,user_name = #{record.userName,age = #{record.age,phone = #{record.phone,jdbcType=VARCHAR}
  <if test="_parameter != null">
   <include refid="Update_By_Example_Where_Clause" />
  </if>
 </update>
</mapper>

各種UUID生成策略，生成的UUID值進行比較。

到此這篇關於Mybatis-Plus BaseMapper的用法詳解的文章就介紹到這了,更多相關Mybatis-Plus BaseMapper內容請搜尋我們以前的文章或繼續瀏覽下面的相關文章希望大家以後多多支援我們！