Based on the changgou project
注意
insert和insertSelective区别
两者的区别在于如果选择insert 那么所有的字段都会添加一遍即使没有值
但是如果使用inserSelective就会只给有值的字段赋值（会对传进来的值做非空判断）
其他后面有Selective字眼的都是这样
Brand table corresponds to Brand entity class
@Table(name="tb_brand")
public class Brand implements Serializable{
@Id
private Integer id;//品牌id
private String name;//品牌名称
private String image;//品牌图片地址
private String letter;//品牌的首字母
private Integer seq;//排序
// getter and setter .....(省略)
}
@Table and @Id are both JPA annotations, @Table is used to configure the mapping relationship between the table and the entity class, and @Id is used to identify the primary key attribute.
1 Enquiry All-Brand List
brandMapper.selectAll();
Generally not used, general queries will use paging
(1) Created by Dao
Create the com.changgou.goods.dao.BrandMapper interface under the changgou-service-goods microservice, the code is as follows:
public interface BrandMapper extends Mapper<Brand> {
}
By inheriting the Mapper interface, the common methods of adding, deleting, modifying and checking are automatically implemented.
(2) Business layer
Create the com.changgou.goods.service.BrandService interface, the code is as follows:
public interface BrandService {
/***
* 查询所有品牌
* @return
*/
List<Brand> findAll();
}
Create a com.changgou.goods.service.impl.BrandServiceImpl implementation class, the code is as follows:
@Service
public class BrandServiceImpl {
@Autowired
private BrandMapper brandMapper;
/**
* 全部数据
* @return
*/
public List<Brand> findAll(){
return brandMapper.selectAll();
}
}
(3) Control layer
Create a controller package under the control layer com.changgou.goods package, and create a class under the package
@RestController
@RequestMapping("/brand")
public class BrandController {
@Autowired
private BrandService brandService;
/***
* 查询全部数据
* @return
*/
@GetMapping
public Result<Brand> findAll(){
List<Brand> brandList = brandService.findAll();
return new Result<Brand>(true, StatusCode.OK,"查询成功",brandList) ;
}
}
2 Query brand based on ID
2.1brandMapper.selectByPrimaryKey(id);
(1) Business layer
Modify the com.changgou.goods.service.BrandService interface and add a method to query brand data based on ID. The code is as follows:
/**
* 根据ID查询
* @param id
* @return
*/
Brand findById(Integer id);
Modify the new method of com.changgou.goods.service.impl.BrandServiceImpl, the code is as follows:
/**
* 根据ID查询
* @param id
* @return
*/
@Override
public Brand findById(Integer id){
return brandMapper.selectByPrimaryKey(id);
}
(2) Control layer
BrandController new method
/***
* 根据ID查询品牌数据
* @param id
* @return
*/
@GetMapping("/{id}")
public Result<Brand> findById(@PathVariable Integer id){
//根据ID查询
Brand brand = brandService.findById(id);
return new Result<Brand>(true,StatusCode.OK,"查询成功",brand);
}
2.2 categoryMapper.select(category);
(1)Service layer
Modify and com.changgou.goods.service.CategoryServiceadd to query all child nodes based on the parent class ID, the code is as follows:
/***
* 根据分类的父ID查询子分类节点集合
*/
List<Category> findByParentId(Integer pid);
Modify and com.changgou.goods.service.impl.CategoryServiceImpladd the above implementation, the code is as follows:
/***
* 根据分类的父节点ID查询所有子节点
* @param pid
* @return
*/
@Override
public List<Category> findByParentId(Integer pid) {
//SELECT * FROM tb_category WHERE parent_id=?
Category category = new Category();
category.setParentId(pid);
return categoryMapper.select(category);
}
(2) Controller layer
Modify and com.changgou.goods.controller.CategoryControlleradd to query all subclass collections based on the parent ID, the code is as follows:
/****
* 根据节点ID查询所有子节点分类集合
*/
@GetMapping(value = "/list/{pid}")
public Result<List<Category>> findByParentId(@PathVariable(value = "pid")Integer pid){
//调用Service实现查询
List<Category> categories = categoryService.findByParentId(pid);
return new Result<List<Category>>(true,StatusCode.OK,"查询成功！",categories);
}
3 New brand
brandMapper.insert(brand);
(1) Business layer
Modify com.changgou.goods.service.BrandService, add a new method
/***
* 新增品牌
* @param brand
*/
void add(Brand brand);
Modify com.changgou.goods.service.impl.BrandServiceImpl and add the brand method code as follows:
/**
* 增加
* @param brand
*/
@Override
public void add(Brand brand){
brandMapper.insert(brand);
}
(2) Control layer
BrandController new method
/***
* 新增品牌数据
* @param brand
* @return
*/
@PostMapping
public Result add(@RequestBody Brand brand){
brandService.add(brand);
return new Result(true,StatusCode.OK,"添加成功");
}
4 Modify the brand
brandMapper.updateByPrimaryKey(brand);
(1) Business layer
Need to change com.changgou.goods.service.BrandService, add the method to modify the brand, the code is as follows:
/***
* 修改品牌数据
* @param brand
*/
void update(Brand brand);
Modify com.changgou.goods.service.impl.BrandServiceImpl, add a method to modify the brand, the code is as follows:
/**
* 修改
* @param brand
*/
@Override
public void update(Brand brand){
brandMapper.updateByPrimaryKey(brand);
}
(2) Control layer
BrandController new method
/***
* 修改品牌数据
* @param brand
* @param id
* @return
*/
@PutMapping(value="/{id}")
public Result update(@RequestBody Brand brand,@PathVariable Integer id){
//设置ID
brand.setId(id);
//修改数据
brandService.update(brand);
return new Result(true,StatusCode.OK,"修改成功");
}
测试：http://localhost:18081/brand/325415
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5 Remove brand
brandMapper.deleteByPrimaryKey(id);
(1) Business layer
Modify com.changgou.goods.service.BrandService, add and delete the brand method, the code is as follows:
/***
* 删除品牌
* @param id
*/
void delete(Integer id);
Modify com.changgou.goods.service.impl.BrandServiceImpl, add a method to delete the brand, the code is as follows:
/**
* 删除
* @param id
*/
@Override
public void delete(Integer id){
brandMapper.deleteByPrimaryKey(id);
}
(2) Control layer
BrandController new method
/***
* 根据ID删除品牌数据
* @param id
* @return
*/
@DeleteMapping(value = "/{id}" )
public Result delete(@PathVariable Integer id){
brandService.delete(id);
return new Result(true,StatusCode.OK,"删除成功");
}
测试：http://localhost:18081/brand/325415
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6 Brand list condition query
brandMapper.selectByExample(example);
(1) Business layer
Modify com.changgou.goods.service.BrandService, add a method to search for brands based on conditions, the code is as follows:
/***
* 多条件搜索品牌方法
* @param brand
* @return
*/
List<Brand> findList(Brand brand);
Modify com.changgou.goods.service.impl.BrandServiceImpl and add the implementation of searching for brands based on multiple conditions. The code is as follows:
/**
* 条件查询
* @param brand
* @return
*/
@Override
public List<Brand> findList(Brand brand){
//构建查询条件
Example example = createExample(brand);
//根据构建的条件查询数据
return brandMapper.selectByExample(example);
}
/**
* 构建查询对象
* @param brand
* @return
*/
public Example createExample(Brand brand){
Example example=new Example(Brand.class);
Example.Criteria criteria = example.createCriteria();
if(brand!=null){
// 品牌名称
if(!StringUtils.isEmpty(brand.getName())){
criteria.andLike("name","%"+brand.getName()+"%");
}
// 品牌图片地址
if(!StringUtils.isEmpty(brand.getImage())){
criteria.andLike("image","%"+brand.getImage()+"%");
}
// 品牌的首字母
if(!StringUtils.isEmpty(brand.getLetter())){
criteria.andLike("letter","%"+brand.getLetter()+"%");
}
// 品牌id
if(!StringUtils.isEmpty(brand.getLetter())){
criteria.andEqualTo("id",brand.getId());
}
// 排序
if(!StringUtils.isEmpty(brand.getSeq())){
criteria.andEqualTo("seq",brand.getSeq());
}
}
return example;
}
(2) Control layer
BrandController new method
/***
* 多条件搜索品牌数据
* @param brand
* @return
*/
@PostMapping(value = "/search" )
public Result<List<Brand>> findList(@RequestBody(required = false) Brand brand){
List<Brand> list = brandService.findList(brand);
return new Result<List<Brand>>(true,StatusCode.OK,"查询成功",list);
}
测试：http://localhost:18081/brand/search
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7 Paging query of brand list
PageHelper.startPage(page,size);
new PageInfo<Brand>(brandMapper.selectAll())
(1) Business layer
Modify com.changgou.goods.service.BrandService to add a paging method, the code is as follows:
/***
* 分页查询
* @param page
* @param size
* @return
*/
PageInfo<Brand> findPage(int page, int size);
Modify com.changgou.goods.service.impl.BrandServiceImpl to add paging method implementation, the code is as follows:
/**
* 分页查询
* @param page
* @param size
* @return
*/
@Override
public PageInfo<Brand> findPage(int page, int size){
//静态分页
PageHelper.startPage(page,size);
//分页查询
return new PageInfo<Brand>(brandMapper.selectAll());
}
(2) Control layer
BrandController new method
/***
* 分页搜索实现
* @param page:当前页
* @param size:每页显示多少条
* @return
*/
@GetMapping(value = "/search/{page}/{size}" )
public Result<PageInfo> findPage(@PathVariable int page, @PathVariable int size){
//分页查询
PageInfo<Brand> pageInfo = brandService.findPage(page, size);
return new Result<PageInfo>(true,StatusCode.OK,"查询成功",pageInfo);
}
8 Brand list conditions + pagination query
PageHelper.startPage(page,size);
Example example = createExample(brand);
PageInfo<Brand>(brandMapper.selectByExample(example));
(1) Business layer
Modify com.changgou.goods.service.BrandService, add a multi-condition paging query method, the code is as follows:
/***
* 多条件分页查询
* @param brand
* @param page
* @param size
* @return
*/
PageInfo<Brand> findPage(Brand brand, int page, int size);
Modify com.changgou.goods.service.impl.BrandServiceImpl and add the multi-condition paging query method code as follows:
/**
* 条件+分页查询
* @param brand 查询条件
* @param page 页码
* @param size 页大小
* @return 分页结果
*/
@Override
public PageInfo<Brand> findPage(Brand brand, int page, int size){
//分页
PageHelper.startPage(page,size);
//搜索条件构建
Example example = createExample(brand);
//执行搜索
return new PageInfo<Brand>(brandMapper.selectByExample(example));
}
(2) Control layer
BrandController new method
/***
* 分页搜索实现
* @param brand
* @param page
* @param size
* @return
*/
@PostMapping(value = "/search/{page}/{size}" )
public Result<PageInfo> findPage(@RequestBody(required = false) Brand brand, @PathVariable int page, @PathVariable int size){
//执行搜索
PageInfo<Brand> pageInfo = brandService.findPage(brand, page, size);
return new Result(true,StatusCode.OK,"查询成功",pageInfo);
}
ze);
//Search criteria construction
Example example = createExample(brand);
//Perform search
return new PageInfo(brandMapper.selectByExample(example));
}
(2)控制层
BrandController新增方法
```java
/***
* 分页搜索实现
* @param brand
* @param page
* @param size
* @return
*/
@PostMapping(value = "/search/{page}/{size}" )
public Result<PageInfo> findPage(@RequestBody(required = false) Brand brand, @PathVariable int page, @PathVariable int size){
//执行搜索
PageInfo<Brand> pageInfo = brandService.findPage(brand, page, size);
return new Result(true,StatusCode.OK,"查询成功",pageInfo);
}