千峰商城-springboot项目搭建-13-tkMapper常用方法之增删改查

1.bean中新建一个实体类Category.java:

 Category.java:

@Data @NoArgsConstructor @AllArgsConstructor public class Category{     private int categoryId;     private String categoryName;     private Integer categoryLevel;     private Integer parentId;     private String categoryIcon;     private String categorySlogan;     private String categoryPic;     private String categoryBgColor;  }

 

  2.创建DAO：   GeneralDAO.java:  (一定不能放到mapperScan能扫描到的包中，要创建一个common包或general包放进去）

public interface GeneraDAO<T> extends Mapper<T>, MySqlMapper<T>{  }

UserDAO.java:

public interface UserDAO extends GeneralDAO<User>{ }

CategoryDAO.java:

public interface CategoryDAO extends GeneralDAO<Category>{ }

 

3.测试(增删改）：

CategoryDAOTest.java:

@RunWith(SpringRunner.class) @SpringBootTest(classes=TkmapperDemoApplication.class) public class CategoryDAOTest{     //添加     @Autowired     private CategoryDAO categoryDAO;      @Test     public void testInsert(){         Category category = new Category(0,测试类别1,1,0,hehe,01.png,hehe,aaa.jpg,black);         int i = categoryDAO.insert(category);         assertEquals(1,i);     }      //修改     @Test     public void testUpdate(){         Category category = new Category(46,测试类别2,1,0,heihei,02.png,hehe,aaa.jpg,black);         int i = categoryDAO.updateByPrimaryKey(category);         assertEquals(1,i);     }           //删除     @Test     public void testDelete(){         int i = categoryDAO.deleteByPrimaryKey(46);         assertEquals(1,i);     } }

 

4.测试(查询）：

CategoryDAOTest.java:

    @Test     //查询所有     public void testSelect1(){     List<Category> category = categoryDAO.selectAll();     for(Category category:categories){         System.out.println(category);     }      //根据主键查询     @Test     public void testSelect2(){         Category category = categoryDAO.selectByPrimaryKey(45);         System.out.println(category);     }      //条件查询     @Test     public void testSelect3(){         Example example = new Example(Category.class);//创建一个example对象封装类别Category查询条件         Example.Criteria carteria = example.createCriteria();         criteria.andEqualTo(categoryLevel,1);//查询类别等于1的数据         criteria.orEqualTo(categoryLevel,2);//查询类别等于1或者2的数据         //criteria.andNotEqualTo(categoryLevel,1);//查询类别不等于1的数据          criteria.andLike(categoryName,%茶%);//查询商品名中带有”茶“字的数据          List<Category> categories = categoryDAO.selectByExample(example);         for(Category category:categories){             System.out.println(category);             }     }      //分页查询     @Test     public void testSelect4(){         int pageNum=2;         int pageSize=10;         int start = (pageNum-1) * pageSize;          RowBounds rowBounds = new RowBounds(start,pageSize);         List<Category> category = categoryDAO.selectByRowBounds(new Category() ,rowBounds);         for(Category category:categories){             System.out.println(category);             }          //查询总记录数         int i = categoryDAO.selectCount(new Category() );         System.out.println(i);     }      //带条件的分页查询     @Test     public void testSelect5(){         Example example = new Example(Category.class);//创建一个example对象封装类别Category查询条件         Example.Criteria carteria = example.createCriteria();         criteria.andEqualTo(categoryLevel,1);//查询类别等于1的数据          int pageNum=1;         int pageSize=3;         int start = (pageNum-1) * pageSize;         RowBounds rowBounds = new RowBounds(start,pageSize);          List<Category> categories = categoryDAO.selectByExampleAndRowBounds(exemple,rowBounds);         for(Category category:categories){             System.out.println(category);             }         //查询满足条件的总记录数         int i = categoryDAO.selectCountByExample(example);         System.out.println(i);     }