New to Laravel, be kind. :-)
I need to connect to a legacy database. I can not make changes to the structure or contents of that database, it is completely read-only.
Can I (and if so: how) create models so that I have "normalized" versions in my app?
E.g.
table 1:
DB column app model
--------------- -----------------------
- My_Title title
- Some_Field1..10 (should not be retrieved)
- Label (int: 0,1,2) label, lookup string from array ["labelA","labelB","labelC"]
table 2:
DB column app model
--------------- -----------------------
- The_Title title
- ...
I can use $hidden, $casts and e.g. public function getLabelAsStringAttribute() + $appends to achieve some of it, but have not found a good / recommended way to :
"rename" columns in the app (not the database), e.g. my_title --> title
only retrieve certain columns; I only need a small subset of fields from the large database; e.g. only retrieve My_Title, Label.
completely replace column content (e.g. Label = 1 --> label = 'labelB')
related: $append adds it to ->toArray(), but not the collection objects themselves. That is indeed how it is documented, but I would like it to be part of the collection/model itself.
Would like this to work in Eloquent queries as well, e.g. App\Movie->where('title','Leon'), where the request to the database should still be querying for My_Title instead of title.
I have the feeling I can use Collection method transform, but it is not clear to me when/where/how to always apply that one when performing a Eloquent query. And/or create a Custom Collection? Like this example, where I could create a method normalize so that I can use \App\Movie->all()->normalize()->first()->title? But that seems to be part of building the query (vs processing the returned DB data) and would still leave me with the unwanted behavior of using the raw DB columns when building a query, e.g. \App\Movie->where("My_Title","Leon")->normalize()->first()->title.
Snippet of WIP:
// todo: enable e.g.
// App\Movie->whereIn('label',['labelB','labelC'])
// which internally treats it as
// App\Movie->whereIn('Label',[1,2])
// example of the final result of the query, with raw DB columns+values
// todo: don't even receive the unwanted columns, only receive "The_Title" and "Label"
$collection = collect([
(Object) ["The_Title"=>"Leon","Some_Field1"=>"ignore me", "Some_Field2"=>"ignore me as well","Label"=>1],
(Object) ["The_Title"=>"Dunkirk","Some_Field1"=>"ignore me","Label"=>2]
]);
// todo: for every collection:
// after data is loaded, transform it to a normalized version of the model
$collection->transform(function ($item, $key) {
return (Object) [
"title"=>$item->The_Title,
"label"=>["labelA","labelB","labelC"][$item->Label]
];
})
// after that it is possible to treat it as a regular collection
$collection->first()->title
Suggestions?
Related
In my Laravel 5.1 app, I have classes Page (models a webpage) and Media (models an image). A Page contains a collection of Media objects and this relationship is maintained in a "media_page" pivot table. The pivot table has columns for page_id, media_id and sort_order.
A utility form on the site allows an Admin to manually associate one or more Media items to a Page and specify the order in which the Media items render in the view. When the form submits, the Controller receives a sorted list of media ids. The association is saved in the Controller store() and update() methods as follows:
[STORE] $page->media()->attach($mediaIds);
[UPDATE] $page->media()->sync($mediaIds);
This works fine but doesn't allow me to save the sort_order specified in the mediaIds request param. As such, Media items are always returned to the view in the order in which they appear in the database, regardless of how the Admin manually ordered them. I know how to attach extra data for the pivot table when saving a single record, but don't know how to do this (or if it's even possible) when passing an array to attach() or sync(), as shown above.
The only ways I can see to do it are:
loop over the array, calling attach() once for each entry and passing along the current counter index as sort_order.
first detach() all associations and then pass mediaIds array to attach() or sync(). A side benefit would be that it eliminates the need for a sort_order column at all.
I'm hoping there is an easier solution that requires fewer trips to the database. Or am I just overthinking it and, in reality, doing the loop myself is really no different than letting Laravel do it further down the line when it receives the array?
[SOLUTION] I got it working by reshaping the array as follows. It explodes the comma-delimited 'mediaIds' request param and loops over the resulting array, assigning each media id as the key in the $mediaIds array, setting the sort_order value equal to the key's position within the array.
$rawMediaIds = explode(',', request('mediaIds'));
foreach($rawMediaIds as $mediaId) {
$mediaIds[$mediaId] = ['sort_order' => array_search($mediaId, $rawMediaIds)];
}
And then sorted by sort_order when retrieving the Page's associated media:
public function media() {
return $this->belongsToMany(Media::class)->orderBy('sort_order', 'asc');
}
You can add data to the pivot table while attaching or syncing, like so:
$mediaIds = [
1 => ['sort_order' => 'order_for_1'],
3 => ['sort_order' => 'order_for_3']
];
//[STORE]
$page->media()->attach($mediaIds;
//[UPDATE]
$page->media()->sync($mediaIds);
I have a product table which has column name unit_id, I have approximate 15 units data. And I stored a custom key of unit to the product as you can check in the screenshot.
And the Units data is stored in settings table, in a single row and meta_value holds all the units data in json format
Now the problem is I have to run two queries every time for products, need help to know more convenient.
// For Products
Product::where('id', 1)->first();
// For settings
Settings::where('meta_key', 'product_units')->first();
Is there any way so that I attach the Settings data in Product model, the problem we get for multiple products not single.
You can try to use a mutator inside the Products model https://laravel.com/docs/5.1/eloquent-mutators.
public function getProductUnitsAttribute() {
return Settings::where('meta_key', 'product_units')->first();
}
so you can do this to get the settings
$product = Product::where('id', 1)->first();
$product->product_units;
but i don't think that this is a good practice.
Being new to attribute routing, I'd like to ask for help getting this to work.
This test is a simple dynamic DB table viewer: Given a table name (or stored query name or whatever) and optionally some WHERE parameters, return query results.
Table COMPANIES (one of any number of tables which has an associated SELECT query stored somewhere, keyed by table name):
ID NAME HQ INDUSTRY
1 Apple USA Consumer electronics
2 Bose USA Low-quality, expensive audio equipment
3 Nokia FIN Mobile Phones
Controller:
[Route("view/{table}/{parameters}")]
public object Get(string table, Dictionary<string, string> parameters) {
var sql = GetSql(table);
var dbArgs = new DynamicParameters(parameters);
return Database.Query(sql, dbArgs); // Return stuff/unrelated to problem
}
SQL stored in some resource or table. Obviously the parameters must match exactly:
SELECT * FROM companies
WHERE name = :name
-- OR hq = :hq
-- OR ...etc. Doesn't matter since it never gets this far.
Request (Should look clean, but the exact URL format isn't important):
www.website.com/view/companies?hq=fin --> 404: No matching controller
www.website.com/view/companies/hq=fin --> parameters is null
www.website.com/view/companies/hq=fin&name=nokia --> Exception: A potentially dangerous Request.Path value was detected from the client (&).
When I use: [Route("view/{table}{parameters}")] I get:
A path segment cannot contain two consecutive parameters. They must be separated by a '/' or by a literal string. Parameter name: routeTemplate. Makes sense.
My question is: How do I accept a table name and any number of unknown parameters in the usual key1=val1&key2=val2 form (not some awkward indexed format like the one mentioned here) which will be later bound to SQL parameters, preferably using a vanilla data structure rather than something like FormCollection.
I don't think that binding URL parameters to a Dictionary is built-in to the framework. I'm sure there's a way to extend it if you wanted to.
I think quickest (but still acceptable) option is to get the query string parameters using Request.GetQueryNameValuePairs() like this:
[Route("view/{table}")]
public object Get(string table) {
Dictionary<string, string> parameters = Request.GetQueryNameValuePairs()
.ToDictionary(x => x.Key, x => x.Value);
var sql = GetSql(table);
var dbArgs = new DynamicParameters(parameters);
return Database.Query(sql, dbArgs); // Return stuff/unrelated to problem
}
how can I build a table of "orders" containing "IdOrder", "Description" and "User"?... the "User" field is a reference to the table "Users", which has "IdUser" and "Name". I'm using repositories.
I have this repository:
Repository<Orders> ordersRepo = new OrderRepo<Orders>(unitOfWork.Session);
to return all Orders to View, I just do:
return View(ordersRepo.All());
But this will result in something like:
IdOrder:1 -- Description: SomeTest -- User: UserProxy123ih12i3123ih12i3uh123
-
When the expected result was:
IdOrder:1 -- Description: SomeTest -- User: Thiago.
PS: I don't know why it returns this "UserProxy123ih12i3123ih12i3uh123". In Db there is a valid value.
The View:
It is showed in a foreach (var item in Model).
#item.Description
#item.User //--> If it is #item.User.Name doesn't work.
What I have to do to put the Name on this list? May I have to do a query using LINQ - NHibernate?
Tks.
What type of ORM are you using? You mention "repositories" but does that mean LinqToSql, Entity Framework, NHibernate, or other?
It looks like you are getting an error because the User field is not loaded as part of the original query. This is likely done to reduce the size of the result set by excluding the related fields from the original query for Orders.
There are a couple of options to work around this:
Set up the repository (or context, depending on the ORM) to include the User property in the result set.
Explicitly load the User property before you access it. Note that this would be an additional round-trip to the database and should not be done in a loop.
In cases where you know that you need the User information it would make sense to ensure that this data in returned from the original query. If you are using LinqToSql take a look at the DataLoadOptions type. You can use this type to specify which relationships you want to retrieve with the query:
var options = new DataLoadOptions();
options.LoadWith<Orders>(o => o.User);
DataContext context = ...;
context.LoadOptions = options;
var query = from o in context.Orders
select o;
There should be similar methods to achive the same thing whatever ORM you are using.
In NHibernate you can do the following:
using (ISession session = SessionFactory.OpenSession())
{
var orders = session.Get<Order>(someId);
NHibernateUtil.Initialize(orders.User);
}
This will result in only two database trips (regardless of the number of orders returned). More information on this can be found here.
In asp.net MVC the foreign key doesn't work the way you are using it. I believe you have to set the user to a variable like this:
User user = #item.User;
Or you have to load the reference sometimes. I don't know why this is but in my experience if I put this line before doing something with a foreign key it works
#item.UserReference.load();
Maybe when you access item.User.Name the session is already closed so NHib cannot load appropriate user from the DB.
You can create some model and initialize it with proper values at the controller. Also you can disable lazy loading for Orders.User in your mapping.
But maybe it is an other problem. What do you have when accessing "#item.User.Name" from your View?
I followed doctrine documnetation to get started. Here is the documentation.
My code is
$User = Doctrine_Core::getTable("User")->find(1);
when I access relations by $User->Phonenumbers, it works. When I convert User object to array by using toArray() method, it does not convert relations to array. It simply display $User data.
Am I missing something?
By using the find method you've only retrieved the User data which is why the return of toArray is limited to that data. You need to specify the additional data to load, and the best place to do this is usually in the original query. From the example you linked to, add the select portion:
$q = Doctrine_Query::create()
->select('u.*, e.*, p.*') // Example only, select what you need, not *
->from('User u')
->leftJoin('u.Email e')
->leftJoin('u.Phonenumbers p')
->where('u.id = ?', 1);
Then when toArray'ing the results from that, you should see the associated email and phonenumber data as well.
I also noticed an anomaly with this where if you call the relationship first then call the ToArray, the relationship somehow gets included. what i mean is that, taking your own eg,
$User = Doctrine_Core::getTable("User")->find(1);
$num= $User->Phonenumbers->office; // assumed a field 'office' in your phone num table
$userArray = $user->toArray(true);
In the above case, $userArray somehow contains the whole relationship. if we remove the $num assignment it doesn't.
am guessing this is due to doctrine only fetching the one record first, and it's only when you try to access foreign key values that it fetches the other related tables