78 lines
2.3 KiB
Java
78 lines
2.3 KiB
Java
package com.example.scaffold.mapper;
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import com.example.scaffold.entity.User;
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import org.apache.ibatis.annotations.*;
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import org.apache.ibatis.cache.impl.PerpetualCache;
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import java.util.List;
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/**
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* User MyBatis Mapper - 演示 MyBatis 注解方式
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*
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* 学习要点：
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* 1. @Mapper - 标记为 MyBatis Mapper 接口
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* 2. @Select/@Insert/@Update/@Delete - SQL 注解
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* 3. @Options - 额外选项（如返回自增ID）
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* 4. @ResultMap - 结果映射
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* 5. @CacheNamespace - 二级缓存
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*/
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@Mapper
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@CacheNamespace
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public interface UserMapper {
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/**
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* 查询所有用户
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*/
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@Select("SELECT * FROM users ORDER BY created_at DESC")
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List<User> findAll();
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/**
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* 根据ID查询 - 使用一级缓存
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*/
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@Select("SELECT * FROM users WHERE id = #{id}")
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User findById(@Param("id") Long id);
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/**
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* 根据用户名模糊查询 - 动态SQL演示
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*/
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@Select("SELECT * FROM users WHERE username LIKE CONCAT('%', #{username}, '%')")
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List<User> findByUsernameLike(@Param("username") String username);
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/**
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* 插入用户 - 返回自增ID
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*/
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@Insert("INSERT INTO users(username, email, phone, bio, active, created_at, updated_at) " +
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"VALUES(#{username}, #{email}, #{phone}, #{bio}, #{active}, NOW(), NOW())")
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@Options(useGeneratedKeys = true, keyProperty = "id")
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int insert(User user);
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/**
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* 更新用户
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*/
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@Update("UPDATE users SET username=#{username}, email=#{email}, phone=#{phone}, " +
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"bio=#{bio}, active=#{active}, updated_at=NOW() WHERE id=#{id}")
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int update(User user);
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/**
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* 删除用户
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*/
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@Delete("DELETE FROM users WHERE id = #{id}")
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int deleteById(@Param("id") Long id);
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/**
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* 统计用户数量
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*/
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@Select("SELECT COUNT(*) FROM users")
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long count();
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/**
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* 批量插入 - 演示脚本SQL
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*/
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@Insert("<script>" +
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"INSERT INTO users(username, email, phone, active, created_at, updated_at) VALUES " +
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"<foreach collection='users' item='u' separator=','>" +
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"(#{u.username}, #{u.email}, #{u.phone}, #{u.active}, NOW(), NOW())" +
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"</foreach>" +
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"</script>")
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int batchInsert(@Param("users") List<User> users);
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} |