I'm trying to query in MongoDB using PHP/CodeIgniter but I can't find a solution...
I have a first query in "function1" where there is
$this->mongo_db->where("category" => getCatID("games");
And in my second function "getCatID" I have
return $this->mongo_db->select('_id')->where("name" => $name)->get('Category');
But it seems that the second function continue on the first query of function1.
I'm using this library...
I assume your first code snippet was intended to be:
$this->mongo_db->where("category", getCatID("games"));
// or…
$this->mongo_db->where(array("category" => getCatID("games")));
I've not used this library, but from perusing the source code, it looks like all query criteria set by where() is accumulated in an internal $wheres property on the Mongo_db class. This only gets cleared by the private _clear() method, which is called from the following public methods:
get()
count()
update()
update_all()
delete()
delete_all()
add_index()
remove_index()
remove_all_indexes()
Any time either of those terminating methods are called, $wheres will be reset. Likewise, if those methods aren't called, older criteria may bleed into your next criteria. In your case getCatID() may be clearing out earlier criteria. PHP is going to execute getCatID() before invoking the where() method in which it's an argument, so I'd expect that outer where() call to see an empty $wheres array.
One solution would be to call getCatID() on its own before building your second query. Alternatively, you could clone the Mongo_db instance to ensure that each query is built independently.
Related
I have a variable $courses that in my debugger is shown as type App/Courses
In the model, there is a one to many relation and I retrieve these related items in the model and then access as $courses->relateditems
In the debugger, $courses->relateditems is shown as type Illuminate/Database/Eloquent/Collection
Ok, all makes sense.
I want to get last item in the $courses->relateditems collection. So I try
$courses->relateditems->last()->startdate
But this is not returning the value that I know exists. And when I evaluate the expression $courses->relateditems->last() in the debugger I get this in my laravel.log:
Symfony\Component\Debug\Exception\FatalErrorException: Cannot access self:: when no class scope is active in /app/Courses.php:68
I am just not sure what is going on. I know I can use DB queries to just get the data I need, but I have a model event triggering a function and that function receives the $courses object/model (or however we name it) and I am just trying to get this working as above.
Ideas on what I am doing wrong?
thanks,
Brian
The issue here based on the error you have at the bottom of your post is a mistake in your code.
However, I think you've misunderstood how Laravel relationships work. They essentially come in two forms on a model, that of a property and that of a method.
relateditems Is a magic property that will return the result of a simple select on the relationship if one has already been performed. If one hasn't been performed it will perform one and then return it, known as eager loading.
relateditems() Is a method that returns a query builder instance for that relationship.
By calling relateditems->last() you're loading ALL related items from the database and then getting the last, which is less than optimal.
The best thing for you to do is this:
$course->relateditems()->orderBy('id', 'desc')->first();
This will get the first item return, however, since we've ordered it by id in descending order, it'll be reversed from what could be considered its default ordering. Feel free to change the id to whatever you want.
Trying to add a new field inside of a document using a field from another table. I first tried to use r.row
r.db('client').table('basic_info').filter({name:'Andre Pastr'}).update({teacher_name: r.db('teacher').table('basic_info').contains(r.row('name').eq('Nicholas Derma')).pluck('id')});
and it returned the message:
e: Cannot use r.row in nested queries. Use functions instead in:
r.db("client").table("basic_info").filter({name: 'Andre Pastr'}).update({"teacher_name": r.db("teacher").table("basic_info").contains(r.row("name").eq("Nicholas Derma")).pluck("id")})
^^^^^
so then after finding this [vague entry][1] in the github issue log I just decided to just change the syntax of my query and run:
r.db('client').table('basic_info').filter({name:'Andre Albuquerque'}).update({teacher_name: r.db('teacher').table('basic_info').filter({name: 'Nicholas Chadwick'}).pluck('id')});
That returned the error message:
: Could not prove argument deterministic. Maybe you want to use the non_atomic flag?
Three inter-related questions: How might I use contains to run such a query? What am I doing wrong with this second query? Why doesn't r.row work in the first query?
You can't use r.row in the first query because it's ambiguous whether it should be bound to contains or to update. (We could define which one it's bound to, but it's very confusing for people because most people haven't memorized all the terms that could possibly bind r.row, so it's easier to force people to name their variables in ambiguous cases.)
You have to specify the non_atomic flag because the function you're passing to update can't be applied atomically (since it isn't deterministic). The way you wrote it, it will be executing a table fetch for every row in the original filter.
You probably want to write something like this instead:
r.table('basic_info').filter({name: 'Nicholas Derma'}).pluck('id').do(function(nderma) {
return r.table('basic_info').filter({name: 'Andre Pastr'}).update({teacher_name: nderma);
})
You should consider creating a secondary index on name and using getAll instead of filter if you run this query often.
I'm trying to get data from an Eloquent query as follows:
$submission->find($id)->first()->with('user', 'clientform')->get();
I'm sending the submission to the view and attempting to access properties from the user model like so:
{{ $submission->clientform->name }}
However, Laravel is throwing the following error:
Undefined property: Illuminate\Database\Eloquent\Collection::$clientform
What am I doing wrong with the way my query is formatted?
You're overdoing it!
Let's break it down:
$submission->find($id);
Will return an instance of the model which corresponds to the entry having the primary key of $id.
$submission->find($id)->first();
This is an unncessary repetition; the find method already gives you a single entry, no need to call first on it.
$submission->find($id)->first()->with('user', 'clientform');
This is where you start going the wrong way; when calling with on a model, Laravel will transform that model into a query builder again, even though it was already resolved by calling find.
$submission->find($id)->first()->with('user', 'clientform')->get();
Finally, the get method resolves the builder into a Illuminate\Support\Collection, regardless of the number of entries found (i.e. it could be a Collection of only one item). It's worth noting, though, that your query will most likely have been fully reset by calling with. It would be the same as instantiating a fresh Submission model and building your query with it. That means you're probably using a collection of all your submission entries, not just the one with $id.
Long story short, this is what you want:
$submission->with('user', 'clientform')->find($id);
It will fetch the matching $id, with the user and clientform relations eager-loaded.
(integer) cast must be done in Homestead for Controller parameter
I am having a hard time searching for the cause of a discrepancy between my local dev environment (Homestead) and the hosted one.
I define a route like this:
Route::get('group/{id}/data', 'GroupDataController#index');
And the code in the Controller looks like this:
public function index($id)
{
return Grouping::all()->where('group_id', $id);
}
Which works fine in production (hosted env), BUT when I execute it locally it throws and empty array [] unless I modify my Controller function to look like this:
public function index($id)
{
return Grouping::all()->where('group_id', (integer)$id);
}
I have no idea of what is going on in here, and I am tired of making changes all over my Controller to make it work on both environments.
I have searched in several place, but maybe I am using incorrect tokens for my search as I have found nothing.
Any help will be really appreciated.
The problem here is that you're not using the correct set of functions.
When you call Grouping::all(), this is actually returning an Eloquent Collection object with every record in your groupings table. You are then calling the where() method on this Collection. This causes two problems: one, it is horribly inefficient; two, the where() method on the Collection works differently than the where() method on the query builder.
The where() method on the Collection takes three parameters: the name of the field, the value in that field on which to filter, and finally a boolean value to tell it whether or not to do a strict comparison (===) or a loose comparison (==). The third parameter defaults to strict. This strict comparison is why you're having the issue you are having, but I cannot explain why one environment sees $id as an integer and the other doesn't.
The where() method on a query builder object will actually add a where clause to the SQL statement being executed, which is a much more efficient way of filtering the data. It also has more flexibility as it is not limited to just equals comparisons (the second parameter is the comparison operator for the where clause, but will default to "=" if it is left out).
You have two options to fix your issue. You can either pass in false as the third parameter to your where() method in the current code (bad), or you can update the code to actually filter using the query instead of filtering on the entire Collection (good).
I would suggest updating your code to this:
public function index($id) {
return Grouping::where('group_id', '=', $id)->get();
}
In the above code, Grouping::where('group_id', '=', $id) will generate a query builder object that has the given where clause, and then get() will execute the query and return the Collection of results.
I marked #patricus (thanks you, so much!) as the correct answer, for he really pointed me in the right direction to understand that there are some keywords that work differently under different contexts (like get()), but I will also point out, how my 2 confusing points were solved in my case:
The difference in my code between production and Homestead development environments was solved by pointing my Homestead to the production database. I am not sure what was the difference (maybe collation or table format), but it gave me a quick out.
I was trying to filter a list of elements in the database but I was constructing it with the wrong logic for Laravel.
To clear what I refer to in the second point, I was using this code:
Grouping::all(['id', 'name_id', 'product_id', 'ship_id'])->where('name_id', '=', $id);
I thought this could work, because it would be selecting all items, with the selected columns, and then filter those with a where clause. But I was wrong, since, as I found out later, the correct way of writing this is:
Grouping::where('name_id', $id)->select('id', 'name_id', 'product_id', 'ship_id')->get();
This is because I forgot completely that I was assembling the query, not writing the actions I expected the program to do.
This second syntax has more logic, since I specify the filter, then put the columns over what was filtered, and finally execute the query with the get() clause.
Of course, it can also be written the other side around for clearer fluent reading:
Grouping::select('id', 'name_id', 'product_id', 'ship_id')->where('name_id', $id)->get();
I have a course table which I need to search based on keywords typed in the search box.
Here is a sample query:
SELECT * FROM Courses WHERE
Title LIKE '%word%' OR Title LIKE '%excel%' OR
Contents LIKE '%word%' OR Contents LIKE '%excel%'
How can I convert this in LINQ where LINQ would dynamically generate WHERE statements based on each keywords.
I tried to user PredicateBuilder it works fine as long as the field is VARCHAR. For the "TEXT" fields the quotes are not generated thus causing compiler to give an error message. Here is the SQL generated by PredicateBuilder
SELECT [t0].[CoursesID], [t0].[Title], [t0].[Contents], [t0].[Active],
FROM [dbo].[Courses] AS [t0]
WHERE ([t0].[Title] LIKE '%word%') OR ([t0].[Contents] LIKE %word%) OR
([t0].Title] LIKE '%excel%') OR ([t0].[Contents] LIKE %excel%)
Notice there is no single Quote for the "Contents" field which is a Text field in the database.
Is there any easy way to build WHERE statement and attach it with query? Does anyone know how I can do this without PredicateBuilder?
Thanks in advance.
Since you are working w/ LINQ I suppose you are working against a LINQ-to-SQL data context right? I don't have a spare DataContext lying around to test this, but this should give you some ideas.
I don't know if it will work against data context though, but most of these are pretty basic stuff (chaining OR operator and Contains method call) so it shouldn't cause problem when the query translates to SQL.
First I create a custom function that would build my predicate:
Func<string, Func<DataItem, bool>> buildKeywordPredicate =
keyword =>
x => x.Title.Contains(keyword)
|| x.Contents.Contains(keyword);
This is a function which takes a single string keyword and then return another function which takes a DataItem and checks it against the keyword.
Basically, if you pass in "Stack", you'll get a predicate: x => x.Title.Contains("Stack") || x.Contents.Contains("Stack").
Next, since there are many possible keywords and you need to chain it with an OR operation, I create another helper function to chain 2 predicates together with an OR
Func<Func<DataItem,bool>, Func<DataItem, bool>, Func<DataItem, bool>> buildOrPredicate =
(pred1, pred2) =>
x => pred1(x) || pred2(x);
This function takes 2 predicates and then join them up with an OR operation.
Having those 2 functions, I can then build my where predicate like this:
foreach (var word in keywords) {
filter = filter == null
? buildKeywordPredicate(word)
: buildOrPredicate(filter, buildKeywordPredicate(word));
}
The first line inside the loop basically checks if the filter is null. If it is, then we want a simple keyword filter built for us.
Else if the filter is not null, we need to chain existing filters with an OR operation, so we pass the existing filter and a new keyword filter to buildOrPredicate to do just that.
And then we can now create the WHERE part of the query:
var result = data.Where(filter);
Passing in the complicated predicate we've just built.
I don't know if this will different from using PredicateBuilder but since we are deferring query translation to the LINQ-to-SQL engine, there should not be any problems.
But as I said, I havn't tested it against a real data context, so if there's any problems you can write in the comments.
Here's the console app that I built to test: http://pastebin.com/feb8cc1e
Hope this helps!
EDIT: For a more generic and reusable version which involves properly utilizing the Expression Trees in LINQ, check out Thomas Petricek's blog post: http://tomasp.net/articles/dynamic-linq-queries.aspx
As predicate builder doesn't know the DB type of the property the Contains method is called on, I guess this might be a problem inside linq to sql. Have you tried with a normal query (not with predicate builder) and a TEXT column with Contains?