我也尝试在使用uuids时使用多态HasAndBelongsToMany关系。我的问题是,我不能教Strongloop使用字符串作为类型的id而不是必要的多对多表中的数字。这会在创建新关系时导致SQL错误。
让我解释一下:
我有两个型号:CartCollection和Cart。一个系列应该有不同类型的推车,包括推车本身。 Cart和CartCollection有uuids而不是简单的id。到目前为止,将此定义为model-json中的属性。问题在于它们之间的多态多对多关系。我尝试使用多态HasAndBelongsToMany关系来实现这一点。在这个表中,我尝试覆盖id-type。
这是我的JSON代码:
{
"name": "SaleCartCollection",
"plural": "SaleCartCollections",
"base": "PersistedModel",
"idInjection": true,
"options": {
"validateUpsert": true
},
"properties": {
"id": {
"type": "string",
"length": 36,
"id": true
}
},
"validations": [],
"relations": {
"saleCartsPoly": {
"type": "hasMany",
"model":"SaleCart",
"polymorphic" : {
"as": "saleCartsPoly",
"invert": true
},
"through": "SaleCartCartCollectionLink"
}
},
"acls": [],
"methods": []
}
{
"name": "SaleCart",
"plural": "SaleCarts",
"base": "PersistedModel",
"idInjection": true,
"options": {
"validateUpsert": true
},
"properties": {
"id": {
"type": "string",
"length": 36,
"id": true
}
},
"validations": [],
"relations": {
"SaleCartCollections": {
"type": "hasAndBelongsToMany",
"model": "SaleCartCollection",
"polymorphic": {
"as":"saleCartsPoly",
"foreignKey" : "saleCartsPolyId",
"discriminator" : "saleCartsPolyType"
},
"through": "SaleCartCartCollectionLink"
}
},
"acls": [],
"methods": []
}
{
"name": "SaleCartCartCollectionLink",
"base": "PersistedModel",
"properties": {
"saleCartsPolyId": {
"type": "string",
"length": 36
}
},
"validations": [],
"relations": {
},
"acls": [],
"methods": []
}
如果我现在尝试将新CartCollection发布到现有购物车,我会得到此输出:
loopback:connector:mysql SQL: INSERT INTO `SaleCartCartCollectionLink`(`saleCartsPolyId`,`saleCartsPolyType`,`saleCartCollectionId`) VALUES(?,?,?), params: [null,"SaleCart","bad7a6fc-1798-49c5-a0cb-fa59eba5b3a4"] +8ms
loopback:connector:mysql Error: {"code":"ER_BAD_FIELD_ERROR","errno":1054,"sqlState":"42S22","index":0} +11ms
我发现这种情况正在发生,因为Strongloop在通过模型中忽略了我的属性定义。它仍然是一个数字,您可以在资源管理器中的模型架构中看到:
[
{
"saleCartsPolyId": 0,
"id": 0,
"saleCartsPolyType": "",
"saleCartCollectionId": ""
}
]
有人知道我做错了什么或者它是Strongloop中的错误吗?
祝你好运
的Niclas
答案 0 :(得分:1)
我是Niclas的同事,我们解决了以下问题。
我们定义
有趣的是,对于HasAndBelongsToMany关系,没有正确设置idType属性。
有人可能想看一下relation-definition.js:1566:
if (params.polymorphic) {
var polymorphic = polymorphicParams(params.polymorphic);
options.polymorphic = polymorphic; // pass through
var accessor = params.through.prototype[polymorphic.as];
if (typeof accessor !== 'function') { // declare once
// use the name of the polymorphic rel, not modelTo
// *** you might want to set idType here: ***
params.through.belongsTo(polymorphic.as, { polymorphic: true });
}
}
CartCartCollectionLink.json
{
"name": "SaleCartCartCollectionLink",
"relations": {
"saleCarts": {
"type": "belongsTo",
"model": "SaleCart",
"foreignKey": "saleCartId",
"polymorphic": {
"as": "saleCart",
"idType": "string"
}
},
"saleCartCollections": {
"type": "belongsTo",
"model": "SaleCartCollection",
"foreignKey": "saleCartCollectionId",
"polymorphic": {
"as": "saleCartCollection",
"idType": "string"
}
}
}
}
Cart.json
{
"name": "SaleCart",
"properties": {
"id": {
"type": "string",
"length": 36,
"id": true
}
},
"relations": {
"saleCartCollections": {
"type": "hasMany",
"model": "SaleCartCollection",
"foreignKey": "saleCartId",
"through": "SaleCartCartCollectionLink",
"polymorphic": {
"as": "saleCart"
}
}
}
}
CartCollection.json
{
"name": "SaleCartCollection",
"properties": {
"id": {
"type": "string",
"length": 36,
"id": true
}
},
"relations": {
"saleCarts": {
"type": "hasMany",
"model": "SaleCart",
"foreignKey": "saleCartCollectionId",
"through": "SaleCartCartCollectionLink",
"polymorphic": {
"as": "saleCartCollection"
}
}
}
}