How to setup a HasAndBelongsToMany association with the same table? - php

Question

What I want
i want to setup a table tasks table with a manyToMany relation between the tasks. One task should have many successors and one can have many predecessors.
My tasks table also has a foreign key to itself, which identifies superior tasks in a oneToMany relation.
The tables look like the following:
tasks(id, superior_task_id, [other attributes])
tasks_predecessors(task_id, pre_id)
Where tasks.id is the primary key, tasks.superior_task_id is a foreign key contraint to tasks and tasks_predecessors.task_id with tasks_predecessors.pre_id is the primary key of tasks_predecesssors, both attributes of tasks_predecessors are foreign keys of tasks.
My status quo
I have tried to use the standard way of creating models from tables: bake in the command line. And used this as my starting point. With this, nothing happend. It was like the tasks_predecessors table didn't exist. The files TasksPredecessors.php and TasksPredecessorsTable.php were created and were fitted with the "belongsTo" associations to the tasks table. In the tasks table, there were one Predecessors association to correct table. With the standard templates and controllers, the data were not accessible.
Now I did some changes to try to set it up as a normal manyToMany relation with both "sides" in one table.
My Code in TasksTable.php:
<?php
declare(strict_types=1);
namespace App\Model\Table;
use Cake\ORM\Query;
use Cake\ORM\RulesChecker;
use Cake\ORM\Table;
use Cake\Validation\Validator;
/**
* Tasks Model
*
* #property \App\Model\Table\ProjectsTable&\Cake\ORM\Association\BelongsTo $Projects
* #property \App\Model\Table\CompaniesTable&\Cake\ORM\Association\BelongsTo $Companies
* #property \App\Model\Table\ToolsTable&\Cake\ORM\Association\BelongsToMany $Tools
*
* #method \App\Model\Entity\Task newEmptyEntity()
* #method \App\Model\Entity\Task newEntity(array $data, array $options = [])
* #method \App\Model\Entity\Task[] newEntities(array $data, array $options = [])
* #method \App\Model\Entity\Task get($primaryKey, $options = [])
* #method \App\Model\Entity\Task findOrCreate($search, ?callable $callback = null, $options = [])
* #method \App\Model\Entity\Task patchEntity(\Cake\Datasource\EntityInterface $entity, array $data, array $options = [])
* #method \App\Model\Entity\Task[] patchEntities(iterable $entities, array $data, array $options = [])
* #method \App\Model\Entity\Task|false save(\Cake\Datasource\EntityInterface $entity, $options = [])
* #method \App\Model\Entity\Task saveOrFail(\Cake\Datasource\EntityInterface $entity, $options = [])
* #method \App\Model\Entity\Task[]|\Cake\Datasource\ResultSetInterface|false saveMany(iterable $entities, $options = [])
* #method \App\Model\Entity\Task[]|\Cake\Datasource\ResultSetInterface saveManyOrFail(iterable $entities, $options = [])
* #method \App\Model\Entity\Task[]|\Cake\Datasource\ResultSetInterface|false deleteMany(iterable $entities, $options = [])
* #method \App\Model\Entity\Task[]|\Cake\Datasource\ResultSetInterface deleteManyOrFail(iterable $entities, $options = [])
*
* #mixin \Cake\ORM\Behavior\TimestampBehavior
*/
class TasksTable extends Table
{
/**
* Initialize method
*
* #param array $config The configuration for the Table.
* #return void
*/
public function initialize(array $config): void
{
parent::initialize($config);
$this->setTable('tasks');
$this->setDisplayField('name');
$this->setPrimaryKey('id');
$this->addBehavior('Timestamp');
$this->belongsTo('UsersCreator', [
'foreignKey' => 'creator_id',
'className' => 'Users'
]);
$this->belongsTo('TasksSup', [
'foreignKey' => 'superior_task_id',
'className' => 'Tasks'
]);
$this->belongsTo('Projects', [
'foreignKey' => 'project_id',
'joinType' => 'INNER',
]);
$this->belongsTo('Companies', [
'foreignKey' => 'company_id',
'joinType' => 'INNER',
]);
$this->hasMany('Predecessors', [
'foreignKey' => 'task_id',
'className' => 'Tasks',
'targetForeignKey' => 'pre_id',
'joinTable' => 'tasks_predecessors'
]);
$this->belongsToMany('Successors', [
'foreignKey' => 'pre_id',
'className' => 'Tasks',
'targetForeignKey' => 'task_id',
'joinTable' => 'tasks_predecessors'
]);
$this->belongsToMany('Tools', [
'foreignKey' => 'task_id',
'targetForeignKey' => 'tool_id',
'joinTable' => 'tasks_tools',
]);
$this->belongsToMany('UsersAssigned', [
'foreignKey' => 'task_id',
'targetForeignKey' => 'user_id',
'joinTable' => 'tasks_users',
'className' => 'Users'
]);
}
/**
* Default validation rules.
*
* #param \Cake\Validation\Validator $validator Validator instance.
* #return \Cake\Validation\Validator
*/
public function validationDefault(Validator $validator): Validator
{
$validator
->nonNegativeInteger('id')
->allowEmptyString('id', null, 'create');
$validator
->scalar('name')
->maxLength('name', 128)
->requirePresence('name', 'create')
->notEmptyString('name');
$validator
->dateTime('start_at')
->allowEmptyDateTime('start_at');
$validator
->dateTime('end_at')
->allowEmptyDateTime('end_at');
$validator
->allowEmptyString('restricted');
$validator
->integer('status')
->allowEmptyString('status');
return $validator;
}
/**
* Returns a rules checker object that will be used for validating
* application integrity.
*
* #param \Cake\ORM\RulesChecker $rules The rules object to be modified.
* #return \Cake\ORM\RulesChecker
*/
public function buildRules(RulesChecker $rules): RulesChecker
{
$rules->add($rules->existsIn('creator_id', 'UsersCreator'), ['errorField' => 'creator_id']);
$rules->add($rules->existsIn('superior_task_id', 'TasksSup'), ['errorField' => 'superior_task_id']);
$rules->add($rules->existsIn('project_id', 'Projects'), ['errorField' => 'project_id']);
$rules->add($rules->existsIn('company_id', 'Companies'), ['errorField' => 'company_id']);
return $rules;
}
}
My code in TasksPredecessorsTable.php:
<?php
declare(strict_types=1);
namespace App\Model\Table;
use Cake\ORM\Query;
use Cake\ORM\RulesChecker;
use Cake\ORM\Table;
use Cake\Validation\Validator;
/**
* TasksPredecessors Model
*
* #property \App\Model\Table\TasksTable&\Cake\ORM\Association\BelongsTo $Tasks
*
* #method \App\Model\Entity\TasksPredecessor newEmptyEntity()
* #method \App\Model\Entity\TasksPredecessor newEntity(array $data, array $options = [])
* #method \App\Model\Entity\TasksPredecessor[] newEntities(array $data, array $options = [])
* #method \App\Model\Entity\TasksPredecessor get($primaryKey, $options = [])
* #method \App\Model\Entity\TasksPredecessor findOrCreate($search, ?callable $callback = null, $options = [])
* #method \App\Model\Entity\TasksPredecessor patchEntity(\Cake\Datasource\EntityInterface $entity, array $data, array $options = [])
* #method \App\Model\Entity\TasksPredecessor[] patchEntities(iterable $entities, array $data, array $options = [])
* #method \App\Model\Entity\TasksPredecessor|false save(\Cake\Datasource\EntityInterface $entity, $options = [])
* #method \App\Model\Entity\TasksPredecessor saveOrFail(\Cake\Datasource\EntityInterface $entity, $options = [])
* #method \App\Model\Entity\TasksPredecessor[]|\Cake\Datasource\ResultSetInterface|false saveMany(iterable $entities, $options = [])
* #method \App\Model\Entity\TasksPredecessor[]|\Cake\Datasource\ResultSetInterface saveManyOrFail(iterable $entities, $options = [])
* #method \App\Model\Entity\TasksPredecessor[]|\Cake\Datasource\ResultSetInterface|false deleteMany(iterable $entities, $options = [])
* #method \App\Model\Entity\TasksPredecessor[]|\Cake\Datasource\ResultSetInterface deleteManyOrFail(iterable $entities, $options = [])
*/
class TasksPredecessorsTable extends Table
{
/**
* Initialize method
*
* #param array $config The configuration for the Table.
* #return void
*/
public function initialize(array $config): void
{
parent::initialize($config);
$this->setTable('tasks_predecessors');
$this->setDisplayField(['task_id', 'pre_id']);
$this->setPrimaryKey(['task_id', 'pre_id']);
$this->belongsToMany('TasksSuc', [
'foreignKey' => 'task_id',
'joinType' => 'INNER',
'className' => 'Tasks'
]);
$this->belongsToMany('TasksPre', [
'foreignKey' => 'pre_id',
'joinType' => 'INNER',
'className' => 'Tasks'
]);
}
/**
* Returns a rules checker object that will be used for validating
* application integrity.
*
* #param \Cake\ORM\RulesChecker $rules The rules object to be modified.
* #return \Cake\ORM\RulesChecker
*/
public function buildRules(RulesChecker $rules): RulesChecker
{
$rules->add($rules->existsIn('task_id', 'TasksSuc'), ['errorField' => 'task_id']);
$rules->add($rules->existsIn('pre_id', 'TasksPre'), ['errorField' => 'pre_id']);
return $rules;
}
}
The $accessible array of tasks looks like the following:
protected $_accessible = [
'name' => true,
'start_at' => true,
'end_at' => true,
'creator_id' => true,
'created' => true,
'modified' => true,
'superior_task_id' => true,
'restricted' => true,
'project_id' => true,
'company_id' => true,
'status' => true,
'users_creator' => true,
'tasks_sup' => true,
'project' => true,
'company' => true,
'predecessors' => true,
'successors' => true,
'tools' => true,
'users_assigned' => true,
];
And in TasksPredecessors.php like this:
protected $_accessible = [
'tasks_suc' => true,
'tasks_pre' => true,
];
I access the data in the tasks_controller like this:
public function view($id = null)
{
$task = $this->Tasks->get($id, [
'contain' => ['UsersCreator', 'TasksSup', 'Projects', 'Companies', 'Successors', 'Tools', 'UsersAssigned', 'Predecessors'],
]);
$this->set(compact('task'));
}
public function add()
{
$task = $this->Tasks->newEmptyEntity();
if ($this->request->is('post')) {
$task = $this->Tasks->patchEntity($task, $this->request->getData(), [
'associated' => ['Tools._joinData'], //adding quantity of tools
]);
if ($this->Tasks->save($task)) {
$this->Flash->success(__('The task has been saved.'));
return $this->redirect(['action' => 'index']);
}
$this->Flash->error(__('The task could not be saved. Please, try again.'));
}
$usersCreator = $this->Tasks->UsersCreator->find('list', ['limit' => 200])->all();
$tasksSup = $this->Tasks->TasksSup->find('list', ['limit' => 200])->all();
$projects = $this->Tasks->Projects->find('list', ['limit' => 200])->all();
$companies = $this->Tasks->Companies->find('list', ['limit' => 200])->all();
$successors = $this->Tasks->Successors->find('list', ['limit' => 200])->all();
$tools = $this->Tasks->Tools->find('list', ['limit' => 200])->all();
$usersAssigned = $this->Tasks->UsersAssigned->find('list', ['limit' => 200])->all();
$this->set(compact('task', 'usersCreator', 'tasksSup', 'projects', 'companies', 'successors', 'tools', 'usersAssigned'));
}
public function edit($id = null)
{
$task = $this->Tasks->get($id, [
'contain' => ['Successors', 'Tools', 'UsersAssigned'],
]);
if ($this->request->is(['patch', 'post', 'put'])) {
$task = $this->Tasks->patchEntity($task, $this->request->getData());
if ($this->Tasks->save($task)) {
$this->Flash->success(__('The task has been saved.'));
return $this->redirect(['action' => 'index']);
}
$this->Flash->error(__('The task could not be saved. Please, try again.'));
}
$usersCreator = $this->Tasks->UsersCreator->find('list', ['limit' => 200])->all();
$tasksSup = $this->Tasks->TasksSup->find('list', ['limit' => 200])->all();
$projects = $this->Tasks->Projects->find('list', ['limit' => 200])->all();
$companies = $this->Tasks->Companies->find('list', ['limit' => 200])->all();
$successors = $this->Tasks->Successors->find('list', ['limit' => 200])->all();
$tools = $this->Tasks->Tools->find('list', ['limit' => 200])->all();
$usersAssigned = $this->Tasks->UsersAssigned->find('list', ['limit' => 200])->all();
$this->set(compact('task', 'usersCreator', 'tasksSup', 'projects', 'companies', 'successors', 'tools', 'usersAssigned'));
}
These are the functions created by the bake command.
My Errors
If I add a task via /tasks/add, everything seems to work properly, until I look it up in the tasks_predecessors table. It still doesn't contain any entry.
If I now try to view one task via /tasks/view/1, the error SQLSTATE[42S22]: Column not found: 1054 Unknown column 'Predecessors.task_id' in 'where clause' comes up, with the corresponding SQL query:
SELECT Predecessors.id AS Predecessors__id, Predecessors.name AS Predecessors__name, Predecessors.start_at AS Predecessors__start_at, Predecessors.end_at AS Predecessors__end_at, Predecessors.creator_id AS Predecessors__creator_id, Predecessors.created AS Predecessors__created, Predecessors.modified AS Predecessors__modified, Predecessors.superior_task_id AS Predecessors__superior_task_id, Predecessors.restricted AS Predecessors__restricted, Predecessors.project_id AS Predecessors__project_id, Predecessors.company_id AS Predecessors__company_id, Predecessors.status AS Predecessors__status FROM tasks Predecessors WHERE Predecessors.task_id in (:c0)
If I try to edit the task, an other error occurs:
Warning (2): array_combine(): Both parameters should have an equal number of elements [CORE\src\ORM\Rule\ExistsIn.php, line 143]
Warning (512): Unable to emit headers. Headers sent in file=C:\xampp\htdocs\Handwerker_Projektmanagement_IP2021\vendor\cakephp\cakephp\src\Error\Debugger.php line=988 [CORE\src\Http\ResponseEmitter.php, line 71]
Warning (2): Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\Handwerker_Projektmanagement_IP2021\vendor\cakephp\cakephp\src\Error\Debugger.php:988) [CORE\src\Http\ResponseEmitter.php, line 168]
Warning (2): Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\Handwerker_Projektmanagement_IP2021\vendor\cakephp\cakephp\src\Error\Debugger.php:988) [CORE\src\Http\ResponseEmitter.php, line 197]
Warning (2): Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\Handwerker_Projektmanagement_IP2021\vendor\cakephp\cakephp\src\Error\Debugger.php:988) [CORE\src\Http\ResponseEmitter.php, line 197]
with
SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'LIMIT 1' at line 1
and the SQL query: SELECT 1 AS existing FROM tasks TasksSuc WHERE LIMIT 1
Conclusion
I can't make an sense of these errors. If I try different things in the controller or ...Table.php files, I will be surprised with different kind of errors, which all don't make sense to me. I hope someone can help me quick, because I could't find anything about this type of relation, which in my opinion is not that uncommon.