I have this schema:
and this relation in model zwz:
public function getAuftrs() {
return $this->hasMany(\app\models\Auftr::className(), ['id' => 'auftr_id'])
->viaTable('znw', ['zwzx_id' => 'id'])
->viaTable('zwz_expl', ['zwz_id' => 'id'])
;}
in the view of zwz:
<?= count($model->getAuftrs()->asArray()->all())
I'm getting:
PHP Notice – yii\base\ErrorException
Undefined index: auftr_id
in C:...\vendor\yiisoft\yii2\db\ActiveRelationTrait.php
And now if I change the two viaTable()s to:
->via('znws')
and of course define this relation before:
public function getZnws() {
return $this->hasMany(\app\models\Znw::className(), ['zwzx_id' => 'id'])
->viaTable('zwz_expl', ['zwz_id' => 'id'])
;}
then it works.
The problem is, that this latter via() way is incompatible with yii2-giiant, so I would like to know what is the difference actually between the two, and how could I keep the original viaTable() way.
github.com/yiisoft/yii2/.../docs/guide/db-active-record.md#chaining-relation-definitions-via-multiple-tables
for me it seems quite clear that we always have to pick the last ID of the chain and define all other IDs backwards. (however in these docs there is via() and not viaTable() and maybe it makes also a difference)
Thanks in advance!
You can not use viaTable() twice on the same relation. The second call will overwrite the first one. If you want to go over more than a junction table you need via(). You can however define multiple relations, one of them using via() and the other using viaTable().
I have no idea how giiant works, but it may detect a Many-Many relation through the fact that viaTable() is used. viaTable() in contrast to via() skips one table so you do not need an ActiveRecord for the junction table. With via() you always define direct relations.
About the order of keys in relation definitions, please check the docs at
http://www.yiiframework.com/doc-2.0/guide-db-active-record.html#declaring-relations
[...] the link between the two types of data: specifies the column(s) through which the two types of data are related. The array values are the columns of the primary data (represented by the Active Record class that you are declaring relations), while the array keys are the columns of the related data.
An easy rule to remember this is, as you see in the example above, you write the column that belongs to the related Active Record directly next to it. You see there that customer_id is a property of Order and id is a property of Customer.
Related
I'm very much a beginner when it comes to database relationships hence what I suspect is a basic question! I have two database tables as follows:
Projects
id
company_id
name
etc...
rfis
id
project_id (foreign key is id on the Projects table above)
Number (this is the column I need help with - more below)
question
The relationships at the Model level for these tables are as follows:
Project
public function rfi()
{
return $this->hasMany('App\Rfi');
}
RFI
public function project()
{
return $this->belongsTo('App\Project');
}
What I'm trying to achieve
In the RFI table I need a system generated number or essentially a count of RFI's. Where I'm finding the difficulty is that I need the RFI number/count to start again for each project. To clarify, please see the RFI table below which I have manually created with the the 'number' how I would like it displayed (notice it resets for each new project and the count starts from there).
Any assistance would be much appreciated!
Todd
So the number field depends on the number of project_id in the RFI table. It is exactly the number of rows with project_id plus one.
So when you want to insert a new row, you calculate number based on project_id and assign it.
RFI::create([
'project_id' => $project_id,
'number' => RFI::where('project_id', $project_id)->count() + 1,
...
]);
What I understood is that you want to set the value of the "number" field to "1" if it's a new project and "increment" if it's an existing project. And you want to automate this without checking for it every time you save a new row for "RFI" table.
What you need is a mutator. It's basically a method that you will write inside the desired Model class and there you will write your own logic for saving data. Laravel will run that function automatically every time you save something. Here you will learn more about mutators.
Use this method inside the "RFI" model class.
public function setNumberAttribute($value)
{
if(this is new project)
$this->attributes['number'] = 1;
else
$this->attributes['number']++;
}
Bonus topic: while talking about mutators, there's also another type of method called accessor. It does the same thing as mutators do, but just the opposite. Mutators get called while saving data, accessors get called while fetching data.
My models have both id and counter attributes. The id is a UUID, and the counter is an integer which is auto-incremented by the database.
Both are unique however I rely on id as the primary key. The counter is just a human-friendly name that I sometimes display to the user.
Immediately before an object is created a listener gives it a UUID. This works fine.
When the record is saved, MySQL increments the counter field. This works fine except that the copy of the object which I have in memory does not have the counter value. I can reload the object to find out what its counter is, but that would require another database query.
Is there a way to find the value of the counter without a specific database query? For example, is it returned as part of the response from the database when a record is created?
Few things:
Use create(array $attributes) and you'll get exactly what you want. For this having right, you have to ensure that $fillable array consists all attributes' names passed to create method.
You should use Observer on model instead of listener (most likely creating method).
Personal preference using Eloquent is that you should use id for id (increment field) and forget custom settings between models because by default it is what relations expect and so on
public function secondModels()
{
return $this->hasMany(SecondModel::class);
}
is pretty much no brainer. But for having this working best way would be (also following recommendations of this guy) FirstModel::id, SecondModel::id, SecondModel::first_model_id; first_models, second_models as table names. Avoiding and/or skipping this kind of unification is lot of custom job afterward. I don't say it can't be done but it is lot of non-first-time-successful work done.
Also, if you want visitor to get something other than id field name, you can make computed field with accessor:
/**
* Get the user's counter.
*
* #return string
*/
public function getCounterAttribute(): string
{
return (string)$this->id;
}
Which you call then with $user->counter.
Also personal preference of mine is to have most possible descriptive variable names so uuid field of mine would be something like
$table->uuid('uuid4');
This is some good and easy to make practice of Eloquent use.
Saying all this let me just to say that create() and save() will return created object from database while insert() shall not do it.
I make a query (with \yii\db\ActiveQuery) with joins, and some fields in "where" clause become ambigous. Is there a nice and short way to specify the name of the current model`s (ActiveRecord) table (from which one the ActiveQuery was instantiated) before the column name? So I can use this all the time in all cases and to make it short.
Don't like doing smth like this all the time (especially in places where there're no joins, but just to be able to use those methods with joins if it will be needed):
// in the ActiveQuery method initialized from the model with tableName "company"
$this->andWhere(['{{%company}}.`company_id`' => $id]);
To make the "named scopes" to work for some cases with joins..
Also, what does the [[..]] mean in this case, like:
$this->andWhere(['[[company_id]]' => $id]);
Doesn't seem to work like to solve the problem described above.
Thx in advance!
P.S. sorry, don't have enough reputation to create tag yii2-active-query
to get real table name :
Class :
ModelName::getTableSchema()->fullName
Object :
$model::getTableSchema()->fullName
Your problem is a very common one and happens most often with fields liek description, notes and the like.
Solution
Instead of
$this->andWhere(['description'=>$desc]);
you simply write
$this->andWhere(['mytable.description'=>$desc]);
Done! Simply add the table name in front of the field. Both the table name and the field name will be automatically quoted when the raw SQL is created.
Pitfall
The above example solves your problem within query classes. One I struggled over and took me quite some time to solve was a models relations! If you join in other tables during your queries (more than just one) you could also run into this problem because your relation-methods within the model are not qualified.
Example: If you have three tables: student, class, and teacher. Student and teacher probably are in relation with class and both have a FK-field class_id. Now if you go from student via class to teacher ($student->class->teacher). You also get the ambigous-error. The problem here is that you should also qualify your relation definitions within the models!
public function getTeacher()
{
return $this->hasOne(Teacher::className(), ['teacher.id' => 'class.teacher_id']);
}
Proposal
When developing your models and query-classes always fully qualify the fields. You will never ever run into this problem again...that was my experience at least! I actually created my own model-gii-template. So this gets solved automatically now ;)
Hope it helped!
I'm a pretty new to Cakephp 3.0 and I'm quite stuck on data validation, or rather Application Rules.
I have a simple user registration form to create a new user in the table 'users'. In the user registration form, there is a field for "ticket_number" where the user has to enter a ticket number which must exist in the table tickets.ticket_number, and also tickets.registration_status must be false (that ticket had not had a user registered with it yet).
My tables look like this (simplified:)
users:
id | username | password
tickets:
id | ticket_number | user_id | registration_status
In my users model, I have defined (user can have many tickets):
$this->hasMany('Tickets', [
'foreignKey' => 'user_id'
]);
In my Tickets model, I have defined (a ticket belongs to a user):
$this->belongsTo('Users', [
'foreignKey' => 'user_id',
'joinType' => 'INNER'
]);
In the users model, I added a rule to attempt to check whether the entered ticket_number exists in the tickets.ticket_number column:
public function buildRules(RulesChecker $rules)
{
$rules->add($rules->isUnique(['username']));
$rules->add($rules->isUnique(['email']));
$rules->add($rules->existsIn
(['ticket_number'], 'Tickets.ticket_number'));
return $rules;
}
This gives me the error:
Error: Call to a member function primaryKey() on a non-object
I'm very stuck here. Can anyone advise on the right approach implementing this check? And then, how to also implement the check to see whether the associated registration_status is 0 (that ticket has not been registered yet).
Thanks in advance for any advice!
--D.
The existsIn rule will not solve your problem, as it will not take your additional condition into account (registration-status).
You will need to provide a custom rule to accomplish the problem you described.
Regarding your update: The rule will return true - so passing the rule, if your tables are not setup correctly or it cannot find the field you are referencing or your field is nullable, check the source here: http://api.cakephp.org/3.0/source-class-Cake.ORM.Rule.ExistsIn.html#74-91
OK, after considerable tinkering, I solved the first issue (On the user add form, the user must enter a ticket number which must exist in the table tickets.ticket_number.)
The only way I could get this to work using an existsIn rule in the UsersTable model, was to declare the ticket_number field as the primary key in the initialize method of the TicketsTable model:
$this->primaryKey('ticket_number');
Then the associations and existsIn rule in the UsersTable model worked. However, this isn't good as I don't want the primary key in tickets permanently set to ticket_number. It also doesn't solve my second problem (checking tickets.registration_status is false.)
So I took a different approach and instead used $this->loadModel('Tickets'); in the add method of my users controller. Then, I could easily perform the required checks:
//Look for this particular ticket
$ticketCount = $this->Tickets->find()->where(['Tickets.ticket_number' => $ticket_number])->count();
$this->set(compact('ticketCount'));
$this->set('_serialize', ['ticketCount']);
//If the ticket isn't found, then return with the Flash error
if (!$ticketCount > 0) {
$this->Flash->error(__('Sorry, but a Ticket with this number could not be found. Please, try again.'));
return;
} //otherwise move on...
I then similarly query the registration status of the ticket, and flash a different error back if it is already registered.
After the checks are passed, it goes on to the normal Add User checks and saving.
While this solution isn't as elegant as what I was hoping to do in the Users model with a custom association and rule, it works.
I'm also not convinced it can't be done in the model with a rule. But for now, this solution works.
Anyway thanks hmic for a response.
DBZ
In Yii 2 RBAC, there is a new table called auth_rule. Can anyone explain its usage with a small example
create table [auth_rule]
(
[name] varchar(64) not null,
[data] text,
[created_at] integer,
[updated_at] integer,
primary key ([name])
);
The basic parts of yiis RBAC-cconcept stayed exactly the same. In both Yii1 and Yii2 you have the following tables:
auth_item: holds the actual rights, groups, roles, etc.
auth_item_child: defines the graph / hierarchy of the items
auth_assignement: assigns an item to a user
In Yii2 you now have a fourth table:
auth_rule: holds reusable rules to check if a right is actually granted
Why is this?
Yii1
The concept behind the rule was already there in Yii1...kind of at least. In Yii1 you had the possibility to define a "bizrule" in auth_item and auth_assignement. "bizrule" and "data" were columns in both those tables.
The contents of the columns were the following:
bizrule: held php-code which had to return a boolean value. This code was executed during rights check with eval(). That way you could control if a right was granted or not even though the user had the item assigned. Example: it makes no sense, but you could give a user a right only on even hours with this bizrule: return date('h') % 2 == 0.
data: held params which could be passed to the bizrule while beeing executed. This data was then available in the scope of the bizrule.
Yii2
The above solution works perfectly, except that the code of a bizrule is not reusable. Therefore this functionality was extracted into its own table.
If you look at the migration-file creating the basic rbac-tables (yii\rbac\migrations\m140506_102106_rbac_init.php) you can see that the item table now has a relation to the rule-table instead of hosting the code in one of its own columns.
There is however no relationship between auth_assignement and auth_rule. In Yii1 this allowed you to disable groups of rights at once. Since you can reuse a rule and attach it to all relevant items this is no longer necessary and was therefore removed.
Example
If you look at the actual implementation of yii\rbac\DbManager and yii\rbac\BaseManager an example shouldn't be necessary. Interesting are the following mthods:
DbManager::addRule(): serializes and persists a rule-instance
DbManager::getRule(): here you can see how the rule is retrieved, unserialized and returned. This means the rule is saved in a serialized format within the data-column of auth_rule.
BaseManager::executeRule(): the rule loaded above is executed via Rule::execute()
If you want to add a rule simply create an instance of yii\rbac\Rule and call DbManager::addRule($rule) with it as its param. This will serialize and save your rule making it reusable elsewhere. Awesome!
Voilà...should be pretty clear now. If you have some open questions or want more details just write a comment.
Cheers and have a good one!
The rule attribute data is serialized.
What does this data look like? Is it like the array below as not yet unserialized?
[
'allow' => true,
'actions' => ['view'],
'roles' => ['viewPost'],
],