springboot+mybatis按条件分页查询多张表的项目实践

public class UserQueryDTO {
    private String name;        // 用户姓名（模糊查询）
    private String province;    // 省份条件 
    private String degree;      // 学历条件 
}

<!-- UserMapper.xml  -->
<select id="selectUserWithConditions" resultMap="UserResultMap">
    SELECT u.id,  u.name,  a.province,  e.degree  
    FROM user u 
    LEFT JOIN address a ON u.id  = a.user_id  
    LEFT JOIN education e ON u.id  = e.user_id  
    <where>
        <if test="name != null and name != ''">
            u.name  LIKE CONCAT('%', #{name}, '%')
        </if>
        <if test="province != null and province != ''">
            AND a.province  = #{province}
        </if>
        <if test="degree != null and degree != ''">
            AND e.degree  = #{degree}
        </if>
    </where>
</select>
 
<resultMap id="UserResultMap" type="UserVO">
    <id property="id" column="id"/>
    <result property="name" column="name"/>
    <result property="province" column="province"/>
    <result property="degree" column="degree"/>
</resultMap>

// 使用PageHelper（需在pom.xml 添加依赖）
public PageInfo<UserVO> queryUsers(UserQueryDTO dto) {
    PageHelper.startPage(dto.getPageNum(),  dto.getPageSize()); 
    List<UserVO> list = userMapper.selectUserWithConditions(dto); 
    return new PageInfo<>(list);
}