Cannot delete data by ID if model has a relation on MySQL

[derrickmehaffy]

Informations

• Node.js version: v10.4.1
• npm version: 6.1.0
• Strapi version: 3.0.0-alpha.12.5
• Database: 10.2.15-MariaDB
• Operating system: Linux Mint 19 Beta (Ubuntu 18.04)

What is the current behavior?

If a model has a relation (in my testing on a fresh clean project, a many to one) you cannot delete data, provided the following error:

TypeError: System.forge(...)[association.alias](...).detach is not a function
    at Promise.all.System.associations.map.association (/mnt/nixstorage/Github/capiv2-dev/api/system/services/System.js:138:51)
    at Array.map (<anonymous>)
    at Object.remove (/mnt/nixstorage/Github/capiv2-dev/api/system/services/System.js:137:27)
    at destroy (/mnt/nixstorage/Github/capiv2-dev/api/system/controllers/System.js:68:35)
    at dispatch (/usr/lib/node_modules/strapi/node_modules/koa-router/node_modules/koa-compose/index.js:44:32)
    at next (/usr/lib/node_modules/strapi/node_modules/koa-router/node_modules/koa-compose/index.js:45:18)
    at dispatch (/usr/lib/node_modules/strapi/node_modules/koa-compose/index.js:42:32)
    at policies.push (/usr/lib/node_modules/strapi/lib/middlewares/router/utils/routerChecker.js:59:26)
    at dispatch (/usr/lib/node_modules/strapi/node_modules/koa-compose/index.js:42:32)
    at module.exports (/mnt/nixstorage/Github/capiv2-dev/plugins/users-permissions/config/policies/permissions.js:24:20)

Steps to reproduce the problem

I created two models system and body which you can see below. Deleting works fine on both system and body if there is no relation between them. However if I add a relation between them, in my case one system can have many body I am provided with the error listed above.

System Model:

{
  "connection": "default",
  "collectionName": "systems",
  "info": {
    "name": "system",
    "description": ""
  },
  "options": {
    "increments": true,
    "timestamps": true,
    "comment": ""
  },
  "attributes": {
    "systemName": {
      "unique": true,
      "type": "string",
      "required": true
    },
    "edsmID": {
      "type": "integer"
    },
    "edsmID64": {
      "type": "float"
    },
    "edsmCoordX": {
      "type": "float"
    },
    "edsmCoordY": {
      "type": "float"
    },
    "edsmCoordZ": {
      "type": "float"
    },
    "edsmCoordLocked": {
      "type": "boolean"
    },
    "bodies": {
      "collection": "body",
      "via": "system"
    }
  }
}

Body Model:

{
  "connection": "default",
  "collectionName": "bodies",
  "info": {
    "name": "body",
    "description": ""
  },
  "options": {
    "increments": true,
    "timestamps": true,
    "comment": ""
  },
  "attributes": {
    "bodyName": {
      "type": "string",
      "required": true
    },
    "system": {
      "model": "system",
      "via": "bodies"
    }
  }
}

What is the expected behavior?

The delete function should work with or without a relation field

Suggested solutions

Modify the services file for MySQL to properly account for relations.

@lauriejim this is a breaking issue with MySQL, Relations, and Deletion.

[derrickmehaffy]

Just confirmed as well that deleting the relation field allows you to delete entries by ID again.

[derrickmehaffy]

Confirmed bug with oneWay Relations on the end model (source model is fine as it doesn't have a relation defined)

[derrickmehaffy]

Also confirmed oneToOne issue on both sides.

[lauriejim]

I'm on master branch and I can't reproduce this issue.

Can you give me the data creation/deletion step you did please.

[derrickmehaffy]

@lauriejim I'm just posting data via postman, delete in the same way

Showing running Strapi:

Model1:

Model2:

Posting data to a model called model1 with no relation data (model has relation setup but not sending data):

Attempting to delete that data via postman:

And a screenshot of the console:

[derrickmehaffy]

Deleting via the AdminUI @lauriejim works fine its when you attempt to delete using the endpoint.

[lauriejim]

I was trying with the content manager. Let me test again with the API.

[derrickmehaffy]

I think the issue is here:

strapi/packages/strapi-generate-api/templates/bookshelf/service.template

Lines 129 to 144 in 3a62e9e

	/**
	* Promise to remove a/an <%= id %>.
	*
	* @return {Promise}
	*/
	remove: async (params) => {
	await Promise.all(
	<%= globalID %>.associations.map(association =>
	<%= globalID %>.forge(params)[association.alias]().detach()
	)
	);
	return <%= globalID %>.forge(params).destroy();
	}
	};

At least comparing it to the Mongo Template here:

strapi/packages/strapi-generate-api/templates/mongoose/service.template

Lines 107 to 146 in 3a62e9e

	/**
	* Promise to remove a/an <%= id %>.
	*
	* @return {Promise}
	*/
	remove: async params => {
	// Select field to populate.
	const populate = <%= globalID %>.associations
	.filter(ast => ast.autoPopulate !== false)
	.map(ast => ast.alias)
	.join(' ');
	// Note: To get the full response of Mongo, use the `remove()` method
	// or add spent the parameter `{ passRawResult: true }` as second argument.
	const data = await <%= globalID %>
	.findOneAndRemove(params, {})
	.populate(populate);
	if (!data) {
	return data;
	}
	await Promise.all(
	<%= globalID %>.associations.map(async association => {
	const search = _.endsWith(association.nature, 'One') || association.nature === 'oneToMany' ? { [association.via]: data._id } : { [association.via]: { $in: [data._id] } };
	const update = _.endsWith(association.nature, 'One') || association.nature === 'oneToMany' ? { [association.via]: null } : { $pull: { [association.via]: data._id } };
	// Retrieve model.
	const model = association.plugin ?
	strapi.plugins[association.plugin].models[association.model || association.collection] :
	strapi.models[association.model || association.collection];
	return model.update(search, update, { multi: true });
	})
	);
	return data;
	}
	};

Though I'm not entirely sure how to fix this myself.

[derrickmehaffy]

Thats if this template is what is being used to generate the files with the adminUI