本文主要说明controller，service，serviceImpl，mapper，xml等运行流程，以select查询为例

流程思路

api.js前端调用接口

import request from '@/utils/request'

// 查询部门列表
export function listDept(query) {
  return request({
    url: '/system/dept/list',
    method: 'get',
    params: query
  })
}

domain.java

package com.energy.core.system.domain;

import com.energy.framework.web.domain.BaseEntity;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;

import javax.validation.constraints.Email;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.Size;
import java.util.ArrayList;
import java.util.List;

/**
 * 部门表 sys_dept
 */
public class SysDept extends BaseEntity {
    private static final long serialVersionUID = 1L;

    /**
     * 部门ID
     */
    private Long deptId;

    /**
     * 父部门ID
     */
    private Long parentId;

    /**
     * 祖级列表
     */
    private String ancestors;

    /**
     * 部门名称
     */
    private String deptName;

    /**
     * 显示顺序
     */
    private String orderNum;

    /**
     * 负责人
     */
    private String leader;

    /**
     * 联系电话
     */
    private String phone;

    /**
     * 邮箱
     */
    private String email;

    /**
     * 部门状态:0正常,1停用
     */
    private String status;

    /**
     * 删除标志（0代表存在 2代表删除）
     */
    private String delFlag;

    /**
     * 父部门名称
     */
    private String parentName;


    private String type;

    private String code;

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    /**
     * 子部门
     */


    private List<SysDept> children = new ArrayList<SysDept>();

    public Long getDeptId() {
        return deptId;
    }

    public void setDeptId(Long deptId) {
        this.deptId = deptId;
    }

    public Long getParentId() {
        return parentId;
    }

    public void setParentId(Long parentId) {
        this.parentId = parentId;
    }

    public String getAncestors() {
        return ancestors;
    }

    public void setAncestors(String ancestors) {
        this.ancestors = ancestors;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    @NotBlank(message = "部门名称不能为空")
    @Size(min = 0, max = 30, message = "部门名称长度不能超过30个字符")
    public String getDeptName() {
        return deptName;
    }

    public void setDeptName(String deptName) {
        this.deptName = deptName;
    }

    @NotBlank(message = "显示顺序不能为空")
    public String getOrderNum() {
        return orderNum;
    }

    public void setOrderNum(String orderNum) {
        this.orderNum = orderNum;
    }

    public String getLeader() {
        return leader;
    }

    public void setLeader(String leader) {
        this.leader = leader;
    }

    @Size(min = 0, max = 11, message = "联系电话长度不能超过11个字符")
    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    @Email(message = "邮箱格式不正确")
    @Size(min = 0, max = 50, message = "邮箱长度不能超过50个字符")
    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public String getDelFlag() {
        return delFlag;
    }

    public void setDelFlag(String delFlag) {
        this.delFlag = delFlag;
    }

    public String getParentName() {
        return parentName;
    }

    public void setParentName(String parentName) {
        this.parentName = parentName;
    }

    public List<SysDept> getChildren() {
        return children;
    }

    public void setChildren(List<SysDept> children) {
        this.children = children;
    }

    @Override
    public String toString() {
        return new ToStringBuilder(this, ToStringStyle.MULTI_LINE_STYLE)
                .append("deptId", getDeptId())
                .append("parentId", getParentId())
                .append("ancestors", getAncestors())
                .append("deptName", getDeptName())
                .append("orderNum", getOrderNum())
                .append("leader", getLeader())
                .append("phone", getPhone())
                .append("email", getEmail())
                .append("status", getStatus())
                .append("delFlag", getDelFlag())
                .append("createBy", getCreateBy())
                .append("createTime", getCreateTime())
                .append("updateBy", getUpdateBy())
                .append("updateTime", getUpdateTime())
                .toString();
    }
}

Controller.java  

@RestController
@RequestMapping("/system/dept") //接口路径
@DataSource(DataSourceType.MASTER)
public class SysDeptController extends BaseController {
    @Autowired
    private ISysDeptService deptService;

    /**
     * 获取部门列表
     */
    @PreAuthorize("@ss.hasPermi('system:dept:list')" //设置权限
    @GetMapping("/list")
    public AjaxResult list(SysDept dept) {
        //调用service层方法
        List<SysDept> depts = deptService.selectDeptList(dept);
        return AjaxResult.success(depts);
    }

}

Service.java

public interface ISysDeptService {
    /**
     * 查询部门管理数据
     * 
     * @param dept 部门信息
     * @return 部门信息集合
     */
    public List<SysDept> selectDeptList(SysDept dept);
}

ServiceImpl.java

@Service
public class SysDeptServiceImpl implements ISysDeptService
{
    @Autowired
    private SysDeptMapper deptMapper;

    /**
     * 查询部门管理数据
     * 
     * @param dept 部门信息
     * @return 部门信息集合
     */
    @Override
    @DataScope(deptAlias = "d")
    public List<SysDept> selectDeptList(SysDept dept)
    {
        return deptMapper.selectDeptList(dept);
    }
}

Mapper.java

public interface SysDeptMapper {
    /**
     * 查询部门管理数据
     * 
     * @param dept 部门信息
     * @return 部门信息集合
     */
    public List<SysDept> selectDeptList(SysDept dept);
}

Mapper.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.energy.core.system.mapper.SysDeptMapper">

	<resultMap type="SysDept" id="SysDeptResult">
		<id     property="deptId"     column="dept_id"     />
		<result property="parentId"   column="parent_id"   />
		<result property="ancestors"  column="ancestors"   />
		<result property="deptName"   column="dept_name"   />
		<result property="orderNum"   column="order_num"   />
		<result property="leader"     column="leader"      />
		<result property="phone"      column="phone"       />
		<result property="email"      column="email"       />
		<result property="status"     column="status"      />
		<result property="delFlag"    column="del_flag"    />
		<result property="parentName" column="parent_name" />
		<result property="createBy"   column="create_by"   />
		<result property="createTime" column="create_time" />
		<result property="updateBy"   column="update_by"   />
		<result property="updateTime" column="update_time" />
	</resultMap>
	
	<sql id="selectDeptVo">
        select d.dept_id, d.parent_id, d.ancestors, d.dept_name, d.order_num, d.leader, d.phone, d.email, d.status, d.del_flag, d.create_by, d.create_time 
        from sys_dept d
    </sql>
    
	<select id="selectDeptList" parameterType="SysDept" resultMap="SysDeptResult">
        <include refid="selectDeptVo"/>
        where d.del_flag = '0'
        <if test="parentId != null and parentId != 0">
			AND parent_id = #{parentId}
		</if>
		<if test="deptName != null and deptName != ''">
			AND dept_name like concat('%', #{deptName}, '%')
		</if>
		<if test="status != null and status != ''">
			AND status = #{status}
		</if>
		<!-- 数据范围过滤 -->
		${params.dataScope}
		order by d.parent_id, d.order_num
    </select>

</mapper>

小结

这里可以根据开篇的流程图进行对照，需要先准备对应数据库，才能写domin，接下来就可以一步一步按照流程图的格式运行