I have 3 tables, standart relation MANY-TO-MANY
Users(id,...) -> Users_Has_Courses(Users_id, Courses_id) -> Courses(id,...)
Courses Model has next relation
'users' => array(self::MANY_MANY, 'Users', 'users_has_courses(Courses_id, Users_id)')
Users Model has next relation
'courses' => array(self::MANY_MANY, 'Courses', 'users_has_courses(Users_id, Courses_id)')
Please, say how I can get list of courses, on which user with specified "id" hasn't been subscribed with CActiveDataProvider ?
Otherwords, I need an analogue of this plain SQL query
select * from Courses where id not in (select Courses_id from users_has_courses where Users_id = 2)
thanks for the help
Instead of a regular "relation", try a parametrized Named Scope to encapsulate the query. In your Courses model, add this scope function to get a list of all the courses the user is not in:
public function userNotIn($user_id)
{
$criteria=new CDbCriteria();
$criteria->condition .= 't.id NOT IN (SELECT users_has_courses.Courses_id FROM users_has_courses WHERE users_has_courses.Users_id = :userid)';
$criteria->params[':userid'] = $user_id;
$this->getDbCriteria()->mergeWith($criteria);
return $this;
}
Then you should be able to do this:
$coursesNotIn=new CActiveDataProvider(Courses::model()->userNotIn($user->id));
This code is completely untested, but it should work in principle. I do this sort of thing often when I have a complex query but I still want to use the AR features, like CActiveDataProvider. Read more about "named scopes" here:
http://www.yiiframework.com/doc/guide/1.1/en/database.ar#parameterized-named-scopes
Good luck!
Related
What I have already and what I'm trying to do:
I have a website that lets users make posts advertising themselves to other users. Now, I'm trying to implement a filter for these posts but filter by values in the users table, posts table and three others. This is where I'm running into some trouble.
Code that works, as is, no filter:
$posts = Post::with('user','lookingfors','playstyles', 'postcomments')->orderBy('id', 'DESC')->paginate(10);
return View::make('posts/index', compact('posts'));
This is what I've tried:
$posts = User::leftjoin('posts', function($join)use($region){
$join->on('users.id', '=', 'posts.user_id');
$join->on('playstyle_post.post_id', '=', 'posts.id'); // join pivot, then join pivot to playstyles
$join->on('playstyle_post.playstyle_id', '=', 'playstyles.id');
//$join->on;
})->where('users.region_id', 'like', $region)->get();
This one keeps bringing up this error:
SQLSTATE[42S22]: Column not found: 1054 Unknown column
'playstyle_post.post_id' in 'on clause' (SQL: select * from users
left join posts on users.id = posts.user_id and
playstyle_post.post_id = posts.id and
playstyle_post.playstyle_id = playstyles.id where
users.region_id like ?) (Bindings: array ( 0 => 6, ))
Also:
$posts = Post::with('lookingfors', 'playstyles', 'postcomments')
->leftjoin('users', 'posts.user_id', '=', 'users.id')
//->join('playstyle_post', 'posts.id', '=', 'playstyle_post.post_id')
->paginate(10);
This one is odd ( well for me ), when 'leftjoin' is commented out obviously it works just as before, but when I have it as it is now it displays the view as it should and even pulls all the right values from the users table but does not display any of the information thats being requested through the 'with'.
I've tried a couple other things in the last two weeks, but I've already thrown them out when they didn't work. This has been kicking my ass for the better half of a month and I can't wrap my head around why I can't get it to work.
So really, my trouble right now is just trying to join the tables and returning it to the view in an eloquent fashion so I can keep treating it the same. The filter itself will be a problem of its own, but getting the joins to work has proved to be the hard part.
Instead of passing a bunch of relationship names to the with() function, try passing an array, setting keys as the names of the relationships and the values as callback functions and pass in the query for actual editing. Also will have to use use ($region) where needed. Hopefully you get the idea.
I put in some examples for adding filters on each relationship. Because you are working locally with each one, you shouldn't have to worry about prefixing them with table names or aliases.
$posts = Post::with(array(
'user' => function($query) use ($region)
{
// User constraints here
$query->where('status', 'A');
$query->where('deleted', '0');
},
'lookingfors' => function($query)
{
// lookingfors constraints here
$query->where('name', 'somelookingforname');
},
'playstyles' => function($query)
{
// playstles constraints here
$query->where('name', 'someplaystylesname');
},
'postcomments' => function($query)
{
// Some postcomments constraints here
$query->where('name', 'somepostcommentsname');
}))
->orderBy('id', 'DESC')
->paginate(10);
Looking at your attempt at left joins though, I don't know if these relationships are correct. My example assumes all the relationships can relate directly back to the user table. Otherwise, you will need to change the keys on the array to match how the relationships should be.
For example, if trying to relate to the playstyles table, but the relationship between playstyles and posts doesn't exist because you need to go through the users table first, you would just change 'playstyles' to 'users.playstyles'.
If you post your migrations, I could help you further.
I have following SQL Query:
SELECT campaigns.* , campaign_countries.points, offers.image
FROM campaigns
JOIN campaign_countries ON campaigns.id = campaign_countries.campaign_id
JOIN countries ON campaign_countries.country_id = countries.id
JOIN offers ON campaigns.offer_id = offers.id
WHERE countries.code = 'US'
This works perfectly well. I want its rails active record version some thing like:
Campaign.includes(campaign_countries: :country).where(countries: {code: "US"})
Above code runs more or less correct query (did not try to include offers table), issue is returned result is collection of Campaign objects so obviously it does not include Points
My tables are:
campaigns --HAS_MANY--< campaign_countries --BELONGS_TO--< countries
campaigns --BELONGS_TO--> offers
Any suggestions to write AR version of this SQL? I don't want to use SQL statement in my code.
I some how got this working without SQL but surely its poor man's solution:
in my controller I have:
campaigns = Campaign.includes(campaign_countries: :country).where(countries: {code: country.to_s})
render :json => campaigns.to_json(:country => country)
in campaign model:
def points_for_country country
CampaignCountry.joins(:campaign, :country).where(countries: {code: country}, campaigns: {id: self.id}).first
end
def as_json options={}
json = {
id: id,
cid: cid,
name: name,
offer: offer,
points_details: options[:country] ? points_for_country(options[:country]) : ""
}
end
and in campaign_countries model:
def as_json options={}
json = {
face_value: face_value,
actual_value: actual_value,
points: points
}
end
Why this is not good solution? because it invokes too many queries:
1. It invokes query when first join is performed to get list of campaigns specific to country
2. For each campaign found in first query it will invoke one more query on campaign_countries table to get Points for that campaign and country.
This is bad, Bad and BAD solution. Any suggestions to improve this?
If You have campaign, You can use campaign.campaign_countries to get associated campaign_countries and just get points from them.
> campaign.campaign_countries.map(&:points)
=> [1,2,3,4,5]
Similarly You will be able to get image from offers relation.
EDIT:
Ok, I guess now I know what's going on. You can use joins with select to get object with attached fields from join tables.
cs = Campaign.joins(campaign_countries: :country).joins(:offers).select('campaigns.*, campaign_countries.points, offers.image').where(countries: {code: "US"})
You can than reference additional fields by their name on Campaign object
cs.first.points
cs.first.image
But be sure, that additional column names do not overlap with some primary table fields or object methods.
EDIT 2:
After some more research I came to conclusion that my first version was actually correct for this case. I will use my own console as example.
> u = User.includes(:orders => :cart).where(:carts => { :id => [5168, 5167] }).first
> u.orders.length # no query is performed
=> 2
> u.orders.count # count query is performed
=> 5
So when You use includes with condition on country, in campaign_countries are stored only campaign_countries that fulfill Your condition.
Try this:
Campaign.joins( [{ :campaign_countries => :countries}, :offers]).where('`countries`.`code` = ?', "US")
I have two tables: users (Users) and groups (Groups).
Users
-----------------
id | username | group
1 | Bob | 2
Groups
-----------------
id | name
1 | firstgroup
2 | secondgroup
I would like to display: users.ID, users.username, group.name (1, Bob, secondgroup)
An SQL statement like so would work:
SELECT Users.id, Users.username, Groups.name
FROM Users
INNER JOIN
Groups ON Groups.id = Users.group
However, I'm struggling to write this in Eloquent, since there is no "FROM". At the moment I'm going for something along the lines of the below, using JOINS (http://laravel.com/docs/queries#joins)
$users = Users::select('id','username', 'Groups.name')->joins('Groups.id', '=', 'id')->get();
Now this isn't working - I think the joins has to come before the select but I just can't work it out :(
I think you're confusing a few things here...
You're mixing Eloquent with the lower-level DB::table('foo')->select() syntax. When you want to use Eloquent I suggest you take a look at the docs about relationships in Eloquent.
You should define your models like so:
class User extends Eloquent {
public function group()
{
return $this->belongsTo('Group', 'group');
// second parameter is necessary because you didnt
// name the column "group_id" but simply "group"
}
}
class Group extends Eloquent {
public function users()
{
return $this->hasMany('User', 'group');
}
}
This sets up all the joins you might be needing later. You can then simply use User::with('group')->all(); and have the query built and run for you.
Database: Query Builder(DB) is not a Eloquent(ORM):
Database query builder you have to inform the table names and the fields, like it says on in your related link of laravel docs: "...provides a convenient, fluent interface to creating and running database queries." like these query below:
$users = DB::table('users')
->join('contacts', 'users.id', '=', 'contacts.user_id')
->join('orders', 'users.id', '=', 'orders.user_id')
->select('users.*', 'contacts.phone', 'orders.price')
->get();
Eloquent is a ORM - Object related Mapping, it means that your class User is related to the table users (look at you files Migrations) and this class extends the Model Class, thus you can access the methods like these bellow:
class User extends Models
{
public static function usersWithGroups(){
return User::select('id', 'name', 'email')->with('groups')->get();
}
}
Observe that method is into the class User, so you can access that in a static way "User::", using Eloquent you'll have many hidden static methods that will improve you time codding, because you are inheriting de Model methods, to more details visit the Eloquent Docs at: Eloquent Docs
DB table:
Mcourse(Master course )-> contains Course Names
Lcourse(Linked
Course- courses belongs to a college) -> contains foreign key
Mcourse_Id. & college Id.
Nw the problem is
I want to display list of courses available in a college using dropdownlist.
So sql query is:
select Lcourse_Id, Mcourse_Name* from Lcourse inner join Mcourse on Lcourse_Mcourse_Id=Mcourse Id..
*Id & value pair for dropdownlist
I could do this usin createCommand..Its working pretty fine. But i cant do this usin Relations ..Help me.
Let's imagine for a minute that your Mcourse table is called courses and model for that table is called Courses, your Lcourse table is called courses_colleges and your colleges table is colleges and model for that table is Colleges
Now, You should have Courses model with relations:
public function relations() {
return array(
'colleges' => array(self::MANY_MANY, 'Colleges', 'courses_colleges(course_id, college_id)')
);
}
Your Colleges model should have similar relations:
public function relations() {
return array(
'courses' => array(self::MANY_MANY, 'Courses', 'courses_colleges(college_id, course_id)')
);
}
Now if you want to print out a dropdown with all courses available for a certain college. In your controller action method get the model of that college including its courses:
public function actionShow() {
$id = 1; // We set just some sample id. You could get it from request ofc.
$college = Colleges::model()->with('courses')->findByPk($id);
$this->render('show', array('college'=>$college));
}
Now in your view print out this:
echo CHtml::dropDownList('courses', '', CHtml::listData($college->courses, 'id', 'name'));
Where 'id' and 'name' are columns of your Courses model.
Something like that.
The error is in the listData() function in your view, specifically that you don't have a mc_Id in your Lcourse model.
As you haven't clarified the model that each of those relationships are assigned with, it's impossible to guess what you should substitute for 'mc_Id' in your view - check your Lcourse model to determine the proper column name.
Sorry to ask all these questions about Kohana. They usually get ignored. I think I just found a bug. I'm making a join between two tables that are not directly related.
$results = ORM::factory('foo')->join("bar")->on("foo.foreign_id", "=", "bar.id");
This generates a query that does not resolve the table names explicitly:
SELECT * FROM `foo` JOIN `bar` ON (`foo`.`foreign_id` = `bar`.`id`)
Which gives (in phpMyAdmin) a table that looks like this:
id time foreign_id blah_int id baz
4 1291851245 3 0 3 52501504
Notice there are two id columns, one for the foo table and one for bar. This is a real problem. Because now, in my results, if I loop through...
foreach ($results as $result) {
echo $result->id; // prints 3!!!
}
Because my results should be foo objects, I expect to get an id of 4, but it's giving me 3 because of the join. Is this a bug in the ORM library? Should I be using a different method to restrict my results from the query? I really don't want to do two separate queries where I load all the bars id's, and then load my foos that way, but it looks like I have to.
You have to use the Database object to build raw queries, not ORM, like this:
$results = DB::select()->from('foo')->join('bar')->on("foo.foreign_id", "=", "bar.id")->execute();
You will need to specific some column aliases however to make your query work unless you use ORM as it was intended.
Using ORM
If you want to use ORM, you need to define the relationships in your model. You mention that they share a relationship with another table so in your case you could use a has many through relationship like this:
protected $_has_many = array(
'bars' => array('model' => 'bar', 'through' => 'other_table', 'foreign_key' => 'foreign_id'),
);
Although your example as given suggests that a straight has_many relationship would work:
protected $_has_many = array(
'bars' => array('model' => 'bar','foreign_key' => 'foreign_id'),
);
This would allow you to access all of the bars using a statement like
$bars = $results->bars->find_all();
foreach($bars as $bar)
{
echo $bar->id; // should echo 4, assuming one record in bars with id 4
}
The Kohana 3.1 ORM Reference Guide is good place to start if you want to learn more about ORM and relationships
Using the Kohana database object and query builder
If you prefer ad hoc queries and are doing joins using the query builder you will likely have colliding column names regardless if you are using Kohana or just raw queries (pop "SELECT * FROM foo JOIN bar ON (foo.foreign_id = bar.id)" into MySQL and you will get the exact same result).
Kohana, just like MySQL allows you to define column aliases for precisely this reason. (See here for more information)
Rewrite your query as follows:
$results = DB::select('id', 'time', 'foreign_id', array('bar.id', 'bar_id'), 'baz')->from('foo')->join("bar")->on("foo.foreign_id", "=", "bar.id")->execute();
This will return:
id time foreign_id blah_int bar_id baz
4 1291851245 3 0 3 52501504