愿大家都能拥有独立开发的项目能力0.0

项目介绍:

  1. 关于crud的模式
  2. 数据库设计
  3. 后端的增删改查接口
  4. 前端的页面调用

crud 下的设计模式:

  • 在业务系统中增删改查(crud)是经常需要开发的内容,本文主要从增删改查来对设计模式进行一个学习或使用.
  • 一般我们对一个表的增删改查有如下一些接口定义
boolean insert(Object o);
Object byId(Integer id);
boolean del(Integer id);
boolean editor(Integer interfaces, Object o;

数据库操作:

创建数据库结构

首先我们使用的是简单的User表的设计

CREATE TABLE `user` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) DEFAULT NULL COMMENT '姓名',
  `age` int(11) DEFAULT NULL COMMENT '年龄',
  `sex` varchar(1) DEFAULT NULL COMMENT '性别',
  `address` varchar(255) DEFAULT NULL COMMENT '地址',
  `phone` varchar(20) DEFAULT NULL COMMENT '电话',
  `create_time` varchar(20) DEFAULT NULL COMMENT '创建时间',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;

创建项目只需要勾选四个即可

 

当然大家也可以使用MybatisPlus 或者JPA都可以  ,Mybatisplus可以不用勾选,在maven中导入mybatisplus依赖即可!!      

 Spring Boot DevTools       

SpringWeb                           

SpringDataJPA 

MySQLDrive

Maven依赖

<dependencies>
<!--添加Springmvc依赖-->
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-web</artifactId>
      </dependency>

 <!-- springBoot JPA的起步依赖 -->
<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

      <!--mysql-->
      <dependency>
          <groupId>mysql</groupId>
          <artifactId>mysql-connector-java</artifactId>
      </dependency>


  </dependencies>

Entity

package com.example.entity;

import javax.persistence.*;

@Entity
@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private Integer age;
    private String sex;
    private String address;
    private String phone;
    @Column(name = "create_time")
    private String createTime;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getPhone() {
        return phone;
    }

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

    public String getCreateTime() {
        return createTime;
    }

    public void setCreateTime(String createTime) {
        this.createTime = createTime;
    }
}

Dao继承JpaRepository

因为我们使用了JPA,所以DAO实现接口就行,不用写太多的方法

package com.example.dao;

import com.example.entity.User;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.stereotype.Repository;

@Repository
public interface UserRepository extends JpaRepository<User, Long> {
    /*
     *带条件的分页查询   
     */
    @Query(value = "select * from user where name like %?1%", nativeQuery = true)
    Page<User> findByNameLike(String name, Pageable pageRequest);
}

Servie层写我们的基本增删改查

package com.example.service;

import com.example.dao.UserRepository;
import com.example.entity.User;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

@Service
public class UserService {

    @Resource
    private UserRepository userRepository;

    /**
     * 注意!id新增
     * 修改不需要id,直接修改
     * @param user
     */
    public void save(User user) {
        String now = new SimpleDateFormat("yyyy-MM-dd").format(new Date());
        user.setCreateTime(now);
        userRepository.save(user);
    }

    /**
     * 根据id删除
     * @param id
     */
    public void delete(Long id) {
        userRepository.deleteById(id);
    }

    /**
     * 根据id查询
     * @param id
     * @return
     */
    public User findById(Long id) {
        return userRepository.findById(id).orElse(null);
    }

    /**
     * 查询全部
     * @return
     */
    public List<User> findAll() {
        return userRepository.findAll();
    }

    /**
     * 分页
     * @param pageNum
     * @param pageSize
     * @param name
     * @return
     */
    public Page<User> findPage(Integer pageNum, Integer pageSize, String name) {
        // 构建分页查询条件
        Sort sort = new Sort(Sort.Direction.DESC, "create_time");
        Pageable pageRequest = PageRequest.of(pageNum - 1, pageSize, sort);
        return userRepository.findByNameLike(name, pageRequest);
    }
}

 创建一个common包用来存储我们的常用的工具类

前后台分离的Vue项目通常使用ajax或者axios请求返回我们的json数据

那么我们需要一个Result类来返回状态信息        还有一个必要的跨域类WebMvcConfig

package com.example.common;

public class Result<T> {
    private String code;
    private String msg;
    private T data;

    public String getCode() {
        return code;
    }

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

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }

    public Result() {
    }

    public Result(T data) {
        this.data = data;
    }

    public static Result success() {
        Result result = new Result<>();
        result.setCode("0");
        result.setMsg("成功");
        return result;
    }

    public static <T> Result<T> success(T data) {
        Result<T> result = new Result<>(data);
        result.setCode("0");
        result.setMsg("成功");
        return result;
    }

    public static Result error(String code, String msg) {
        Result result = new Result();
        result.setCode(code);
        result.setMsg(msg);
        return result;
    }
}

package com.example.common;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * 描述:
 * 作者: xq
 * 日期: 2020/5/8 13:28
 **/
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedHeaders("Content-Type","X-Requested-With","accept,Origin","Access-Control-Request-Method","Access-Control-Request-Headers","token")
                .allowedMethods("*")
                .allowedOrigins("*")
                .allowCredentials(true);
    }
}

yml的配置类       配置了最基本的

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: root
    url: jdbc:mysql://localhost:3306/mytest?useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&useSSL=false&serverTimezone=GMT%2b8

现在我们的基本配置已经完成,来到我们的vue前端了

包括还有一部分js文件,需要的可以联系我

当然也可以在element官网自己引用   官网地址如下:

组件 | Element

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>用户信息</title>
    <!-- 引入样式 -->
    <link rel="stylesheet" href="element.css">
</head>
<body>
<div id="app" style="width: 80%; margin: 0 auto">
    <h2>用户信息表</h2>

    <el-row>
        <el-col :span="6" style="margin-bottom: 10px">
            <el-button type="primary" @click="add">新增</el-button>
            <el-input v-model="name" style="width: 70%" @keyup.enter.native="loadTable(1)"></el-input>
        </el-col>
    </el-row>

    <el-table
            :data="page.content"
            stripe
            border
            style="width: 100%">
        <el-table-column
                prop="name"
                label="用户名"
        >
        </el-table-column>
        <el-table-column
                prop="age"
                label="年龄"
                width="180">
        </el-table-column>
        <el-table-column
                prop="sex"
                label="性别">
        </el-table-column>
        <el-table-column
                prop="address"
                label="地址">
        </el-table-column>
        <el-table-column
                prop="phone"
                label="电话">
        </el-table-column>
        <el-table-column
                fixed="right"
                label="操作"
                width="100">
            <template slot-scope="scope">
                <el-button type="primary" icon="el-icon-edit" size="small" circle @click="edit(scope.row)"></el-button>
                <el-button type="danger" icon="el-icon-delete" size="small" circle @click="del(scope.row.id)"></el-button>
            </template>
        </el-table-column>
    </el-table>
    <el-row type="flex" justify="center" style="margin-top: 10px">
        <el-pagination
                layout="prev, pager, next"
                :page-size="pageSize"
                :current-page="pageNum"
                @prev-click="loadTable"
                @current-change="loadTable"
                @next-click="loadTable"
                :total="page.totalElements">
        </el-pagination>
    </el-row>

    <el-dialog
            title="用户信息"
            :visible.sync="dialogVisible"
            width="30%">
        <el-form ref="form" :model="form" label-width="80px">
            <el-form-item label="用户名">
                <el-input v-model="form.name"></el-input>
            </el-form-item>
            <el-form-item label="年龄">
                <el-input v-model="form.age"></el-input>
            </el-form-item>
            <el-form-item label="性别">
                <el-radio v-model="form.sex" label="男">男</el-radio>
                <el-radio v-model="form.sex" label="女">女</el-radio>
            </el-form-item>
            <el-form-item label="地址">
                <el-input v-model="form.address"></el-input>
            </el-form-item>
            <el-form-item label="电话">
                <el-input v-model="form.phone"></el-input>
            </el-form-item>
        </el-form>
        <span slot="footer" class="dialog-footer">
            <el-button @click="dialogVisible = false">取 消</el-button>
            <el-button type="primary" @click="save">确 定</el-button>
        </span>
    </el-dialog>

</div>

<script src="jquery.min.js"></script>
<script src="vue.js"></script>
<!-- 引入组件库 -->
<script src="element.js"></script>

<script>
    new Vue({
        el: '#app',
        data: {
            page: {},
            name: '',
            pageNum: 1,
            pageSize: 8,
            dialogVisible: false,
            form: {}
        },
        created() {
            this.loadTable(this.pageNum);
        },
        methods: {
            loadTable(num) {
                this.pageNum = num;
                $.get("/user/page?pageNum=" + this.pageNum + "&pageSize=" + this.pageSize + "&name=" + this.name).then(res => {
                    this.page = res.data;
                });
            },
            add() {
                this.dialogVisible = true;
                this.form = {};
            },
            edit(row) {
                this.form = row;
                this.dialogVisible = true;
            },
            save() {
                let data = JSON.stringify(this.form);
                if (this.form.id) {
                    // 编辑
                    $.ajax({
                        url: '/user',
                        type: 'put',
                        contentType: 'application/json',
                        data: data
                    }).then(res => {
                        this.dialogVisible = false;
                        this.loadTable(1);
                    })
                } else {
                    // 新增
                    $.ajax({
                        url: '/user',
                        type: 'post',
                        contentType: 'application/json',
                        data: data
                    }).then(res => {
                        this.dialogVisible = false;
                        this.loadTable(1);
                    })
                }
            },
            del(id) {
                $.ajax({
                    url: '/user/' + id,
                    type: 'delete',
                    contentType: 'application/json'
                }).then(res => {
                    this.loadTable(1);
                })
            }
        }
    })
</script>
</body>
</html>

Control层的编写

package com.example.controller;

import com.example.common.Result;
import com.example.entity.User;
import com.example.service.UserService;
import org.springframework.data.domain.Page;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {

    @Resource
    private UserService userService;

    // 新增用户
    @PostMapping
    public Result add(@RequestBody User user) {
        userService.save(user);
        return Result.success();
    }

    // 修改用户
    @PutMapping
    public Result update(@RequestBody User user) {
        userService.save(user);
        return Result.success();
    }

    // 删除用户
    @DeleteMapping("/{id}")
    public void delete(@PathVariable("id") Long id) {
        userService.delete(id);
    }

    // 根据id查询用户
    @GetMapping("/{id}")
    public Result<User> findById(@PathVariable Long id) {
        return Result.success(userService.findById(id));
    }

    // 查询所有用户
    @GetMapping
    public Result<List<User>> findAll() {
        return Result.success(userService.findAll());
    }

    // 分页查询用户
    @GetMapping("/page")
    public Result<Page<User>> findPage(@RequestParam(defaultValue = "1") Integer pageNum,
                                       @RequestParam(defaultValue = "10") Integer pageSize,
                                       @RequestParam(required = false) String name) {
        return Result.success(userService.findPage(pageNum, pageSize, name));
    }

}

感谢大家观看!!

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