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简单的CRUD

public interface IUserDao {
   /*** 查询所有用户* @return*/@Select("select * from user")@Results(id="userMap",value= {
   @Result(id=true,column="id",property="userId"),@Result(column="username",property="userName"),@Result(column="sex",property="userSex"),@Result(column="address",property="userAddress"),@Result(column="birthday",property="userBirthday")})List
   
     findAll();/*** 根据 id 查询一个用户* @param userId* @return*/@Select("select * from user where id = #{uid} ")@ResultMap("userMap")User findById(Integer userId);/*** 保存操作* @param user，这里user存入之后user中有了id属性* @return 影响行数*/@Insert("insert into user(username,sex,birthday,address)values(#{
   username},#{
   sex},#{
   birthday},#{
   address})")//@Options(useGeneratedKeys = true , keyProperty = "id",keyColumn = "id")，这也可以让user有id属性@SelectKey(keyColumn="id",keyProperty="id",resultType=Integer.class,before = false, statement = {
    "select last_insert_id()" })int saveUser(User user);/*** 更新操作* @param user* @return*/@Update("update user set username=#{
   username},address=#{
   address},sex=#{
   sex},birthday=#{
   birthday} where id =#{
   id} ")int updateUser(User user);/*** 删除用户* @param userId* @return*/@Delete("delete from user where id = #{uid} ")int deleteUser(Integer userId);/*** 查询使用聚合函数* @return*/@Select("select count(*) from user ")int findTotal();/*** 模糊查询* @param name* @return*/@Select("select * from user where username like #{username} ")List
    
      findByName(String name);}//通过注解方式，我们就不需要再去编写 UserDao.xml 映射文件了
    
   

一对多查询

@CacheNamespace(blocking = true)public interface IUserDao {
       /**     * 返回查询所有     * @return     */    @Select("select * from user")    @Results(id="userMap",value = {
               @Result(id = true,property = "userId",column = "id"),            @Result(property = "userName",column = "username"),            @Result(property = "userSex",column = "sex"),            @Result(property = "userBirthday",column = "birthday"),            @Result(property = "userAddress",column = "address"),            @Result(property = "accounts",column = "id",many = @Many(select = "cn.qut.dao.IAccountDao.findByUid",fetchType = FetchType.LAZY))    })    List
   
     findAll();    /**     * 根据id返回用户     * @return     */    @ResultMap("userMap")    @Select("select * from where id=#{id}")    User findById();}
   

测试类：

在这里插入代码片

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