web开发遇到的问题与解决思路

最近开发一个船舶项目，遇到的问题

[问题][6]：一个船舶上物料有很多分类,分类下面还存在分类,分类下面还存在分类，有一些分类下面只存在2级关系分类，有的是3级，有的是4级,如果是最终的类别还要带具体物料的名字以及基本信息：

[解决思路][6]：

1.创建表结构

以下为关键字段

字段名字	类型	备注
storesId	bigint(20)	物料ID，主键
parentId	bigint(20)	父类id
name	varchar(64)	物料名称
storesType	varchar(64)	物料or类别

2.由于主键唯一性,所以parentId放上一类别的主键id，依次循环放置parentId，然后循环查询出来就行里,这样依赖，看似解决了，问题出在查询这里，因为存在2级3级4级等不同的依赖关系，查询要查询多少次呢？查询2次不行，4次也不行。

3.然后只能用递归查询来解决问题了，[代码如下][6]



4.查询以json格式传回前端页面

{
"code": "200",
"message": "OK",
"data": [
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463977621000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463977786000,
"storesId": 10067,
"storesType": "CATEGORY",
"code": "WL0002",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 0,
"children": [
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463987635000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463987727000,
"storesId": 10070,
"storesType": "CATEGORY",
"code": "SS0001",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 10067,
"children": [
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463991922000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463991922000,
"storesId": 10078,
"storesType": "CATEGORY",
"code": "SS0011",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 10070,
"children": [
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463991946000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463991946000,
"storesId": 10079,
"storesType": "CATEGORY",
"code": "SS0012",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 10078,
"children": null
}
]
}
]
},
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463987643000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463987732000,
"storesId": 10071,
"storesType": "CATEGORY",
"code": "SS0002",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 10067,
"children": null
}
]
},
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463977646000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463977787000,
"storesId": 10068,
"storesType": "CATEGORY",
"code": "WL0003",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 0,
"children": [
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463991817000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463991816000,
"storesId": 10076,
"storesType": "CATEGORY",
"code": "SS0009",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 10068,
"children": null
},
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463991865000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463991864000,
"storesId": 10077,
"storesType": "CATEGORY",
"code": "SS0010",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 10068,
"children": null
}
]
},
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463977660000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463977790000,
"storesId": 10069,
"storesType": "CATEGORY",
"code": "WL0004",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 0,
"children": null
},
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463991048000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463991047000,
"storesId": 10072,
"storesType": "CATEGORY",
"code": "SS0003",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 0,
"children": null
},
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463991240000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463991240000,
"storesId": 10073,
"storesType": "CATEGORY",
"code": "SS0004",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 0,
"children": null
},
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463991611000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463991611000,
"storesId": 10074,
"storesType": "CATEGORY",
"code": "SS0005",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 0,
"children": null
},
{
"displayOrder": 4,
"status": "NORMAL",
"createBy": 1,
"createTime": 1463991811000,
"updateBy": 0,
"updateTime": null,
"version": 0,
"lastUpdate": 1463991815000,
"storesId": 10075,
"storesType": "CATEGORY",
"code": "SS0008",
"name": "物料2号",
"specification": "12×1",
"description": "没有描述",
"unit": "T",
"parentId": 0,
"children": null
}
]
}

5.如果有更好的解决思路,可以留言交流。