java从表中查询树结构的xml_public interface factorymapper extends basemapper<-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_45433217/article/details/115401807

这篇博客介绍了如何使用Java、MyBatis和实体类构建从数据库查询的树形结构。通过Factory实体类、FactoryMapper接口及其XML配置，展示了获取区域树形菜单的方法，实现了根据LocalNo查询并展示包含子节点的工厂数据。

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java从数据库查询树结构

实体类

@Data
@EqualsAndHashCode(callSuper = false)
@TableName("t_000_factory")
@ApiModel(value="Factory对象", description="Factory对象")
public class Factory implements Serializable {

    @TableId(value = "FactoryId")
    private Long FactoryId;
    
    @TableField("FactoryName")
    private String FactoryName;
	
	@TableField("LocalNo")
    private Long LocalNo;

    // 子元素
    @TableField(exist = false)
    private List<Factory> children;
}

Mapper

@Repository
public interface FactoryMapper extends BaseMapper<Factory> {
    //获取区域树形菜单
    public List<Factory> getFactoryTree(Long localNo);
}

Mapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.community.manage.dao.Factory.FactoryMapper">

    <resultMap type="com.community.manage.model.Factory.Factory" id="factoryResult">
        <id column="factoryId" property="factoryId"/>
        <result column="LocalNo" property="localNo"/>
        <result column="FactoryName" property="factoryName"/>
        <collection column="factoryId" property="children" ofType="com.community.manage.model.Factory.Factory"
                    select="getFactoryTree"></collection>
    </resultMap>
    
    <select id="getFactoryTree" resultMap="factoryResult" parameterType="long">
        select * from t_000_factory where
            LocalNo=#{localNo} and IsDel!=1 order by FactoryNo
    </select>
</mapper>