This is the sample code :
$r = $coll->findOne();
$coll->remove(array("_id"=>$r["_id"])); // use the same object id as retreived from DB
$ret=$coll->findOne(array("_id"=>($r["_id"])));
var_dump($ret); // dumps the records that was supposed to be deleted
The records in the collection have MongoDB objectId, and not strings.
Same logic on console works fine and deleted the record correctly.
This is working for me. Here's the code:
$coll->drop();
print("Now have ".$coll->count()." items\n");
$coll->insert(array("x" => 'blah'));
$coll->insert(array("x" => "blahblah"));
print("Inserted ".$coll->count()." items\n");
$x = $coll->findOne();
print("Object X\n");
print_r($x);
$query_x = array('_id' => $x['_id']);
$coll->remove($query_x);
print("Removed 1 item, now have ".$coll->count()." items\n");
$y = $coll->findOne($query_x);
print("Object Y\n");
print_r($y);
Here's the output:
Now have 0 items
Inserted 2 items
Object X
Array
(
[_id] => MongoId Object
(
[$id] => 4d8d124b6803fa623b000000
)
[x] => blah
)
Removed 1 item, now have 1 items
Object Y
Are you sure there's not a typo somewhere?
Unlike the php == operator, mongo's equality operator always uses "Object equality" which is like php's identical comparison operator (===) or java's .equals(). While your code looks as though it should work (and it does work fine for me with a test dataset), something about your dataset may be causing php to cast the returned MongoId to a string. Read more about MongoId here.
Make sure that your query is supplying a MongoId for comparison by doing a var_dump of the query itself. Also, make sure that you are running the latest version of the PHP Mongo driver.
Since PHP is loosely typed it is most important to ensure that you cast all input values and search values to the expected and consistent data type otherwise it will surely not locate your expected document.
While using MongoDB within PHP I make it a point to cast everything intentionally in order to avoid any possible confusion or error.
Also, the mongodb-user group at groups.google.com is very good and responsive so if you are not already utilizing that resource I would definitely consider joining it.
Related
I have the following problem - I want to test REST api with Codeception.
When I want to make sure in JSON response I have array:
'data' => [
'sth' => 'whathever'
]
I can use seeResponseJsonMatchesXpath this way:
$I->seeResponseJsonMatchesXpath('//data/sth');
But what to do if I want to make sure I don't have in response sth? I would like to use for example:
$I->seeResponseJsonMatchesXpath('//data');
$I->dontSeeResponseJsonMatchesXpath('//data/sth');
but obviously there is no dontSeeResponseJsonMatchesXpath method in Codeception.
I also don't know what will be exact value in sth so probably I cannot use here dontSeeResponseContainsJson.
The question is - how to make the following check?
(Disclaimer: Entirely unfamiliar with codeception, only with XPath)
JSON is not supposed to be checked against XPath. But the check you could probably do is
$I->seeResponseJsonMatchesXpath('not(//data/sth)');
Which would return true or 1 if there is no data and sth - and false or 0 if there is.
EDIT: As a response to your comments:
Probably this is something close I need but I want to make sure only sth is not present inside data whereas data should exist (but I don't need to check it in this expression)
The expression already does exactly that - not(//data/sth) returns false for a document like
<data>
<sth/>
</data>
but returns true for a document containing data only:
<data/>
or anything else. But it seems to me there could be pitfalls with converting JSON to XML.
I checked both solutions - yours and //data/not(sth) but it doesn't seem to work
Yes, that does not work because you are using an XPath 1.0 engine. Your attempt would be a valid XPath 2.0 expression. Use the following expression to independently test data and sth:
//data and not(//data/sth)
This only returns true if at least one data element exists and if there is no data element that has an sth element as a child.
I know this has been asked before, but I have yet to find a solution that works efficiently. I am working with the MongoDB C# driver, though this is more of a general question about MongoDB operations.
I have a document structure that looks something like this:
field1: value1
field2: value2
...
users: [ {...user 1 subdocument...}, {...user 2 subdocument...}, ... ]
Some facts:
Each user subdocument includes further sub-arrays & subdocuments (so they're fairly complex).
The average users array only contains about 5 elements, but in the worst case can surpass 100.
Several thousand update operations on multiple users may be conducted per day in this system, each on one document at a time. Larger arrays will receive more frequent updates due to their data size.
I am trying to figure out how to do this efficiently. From what I've heard, you cannot directly set several array elements to new values all at once, so I had to try something else.
I tried using the $pullAll / $AddToSet + $each operations to remove the old array and replace it with a modified one. I am aware that $pullall can remove only the elements that I need as well, but I would like to preserve the order of elements.
The C# code:
try
{
WriteConcernResult wcr = collection.Update(query,
Update.Combine(Update.PullAll("users"),
Update.AddToSetEach("users", newUsers.ToArray())));
}
catch (WriteConcernException wce)
{
return wce.Message;
}
In this case newUsers is aList<BsonValue>converted to an array. However I am getting the following exception message:
Cannot update 'users' and 'users' at the same time
By the looks of it, I can't have two update statements in use on the same field in the same write operation.
I also tried Update.Set("users", newUsers.ToArray()), but apparently the Set statement doesn't work with arrays, just basic values:
Argument 2: cannot convert from 'MongoDB.Bson.BsonValue[]' to 'MongoDB.Bson.BsonValue'
So then I tried converting that array to a BsonDocument:
Update.Set("users", newUsers.ToArray().ToBsonDocument());
And got this:
An Array value cannot be written to the root level of a BSON document.
I could try replacing the whole document, but that seems like overkill and definitely not very efficient.
So the only thing I can think of now is to run two separate write operations: one to remove the unwanted old users and another to replace them with their newer versions:
WriteConcernResult wcr = collection.Update(query, Update.PullAll("users"));
WriteConcernResult wcr = collection.Update(query, Update.AddToSetEach("users", newUsers.ToArray()));
Is this my best option? Or is there another, better way of doing this?
Your code should work with a minor change:
Update.Set("users", new BsonArray(newUsers));
BsonArray is a BsonValue, where as an array of documents is not and we don't implicitly convert arrays like we do other primitive values.
this extension method solve my problem:
public static class MongoExtension
{
public static BsonArray ToBsonArray(this IEnumerable list)
{
var array = new BsonArray();
foreach (var item in list)
array.Add((BsonValue) item);
return array;
}
}
Im trying to 'compare' all documents between 2 collections, which will return true only and if only all documents inside 2 collections are exactly equal.
I've been searching for the methods on the collection, but couldnt find one that can do this.
I experimented something like these in the mongo shell, but not working as i expected :
db.test1 == db.test2
or
db.test1.to_json() == db.test2.to_json()
Please share your thoughts ! Thank you.
You can try using mongodb eval combined with your custom equals function, something like this.
Your methods don't work because in the first case you are comparing object references, which are not the same. In the second case, there is no guarantee that to_json will generate the same string even for the objects that are the same.
Instead, try something like this:
var compareCollections = function(){
db.test1.find().forEach(function(obj1){
db.test2.find({/*if you know some properties, you can put them here...if don't, leave this empty*/}).forEach(function(obj2){
var equals = function(o1, o2){
// here goes some compare code...modified from the SO link you have in the answer.
};
if(equals(ob1, obj2)){
// Do what you want to do
}
});
});
};
db.eval(compareCollections);
With db.eval you ensure that code will be executed on the database server side, without fetching collections to the client.
is there a preferred way to check for existing documents via mongoid?
if i do Model.find('id')', and the id is nil or the document doesn't exist, it throws an exception... i want it to return an empty array.
if i do Model.where(:id => 'id'), and the id is nil, it returns all the documents... i also want it to return an empty array.
and then with Model.criteria(:id => 'id').to_a, for whatever reason never returns a result, even with a valid object id. not sure what is going on there...
but basically with activerecord i would just use the exists? finder method, so i am looking for the mongoid alternative.
In Mongoid 2.0, Following seems to do what you want:
User.all.for_ids('4d9ad01de1607c4bc000001a').entries
I implemented the pearson product correlation via map / reduce / finalize. The missing part is to restrict the documents (representing users) to be processed via a filter query. For a simple query like
mapreduce(mapper, reducer, :finalize => finalizer, :query => { :name => 'Bernd' })
I get this to work.
But my filter criteria is a little bit more complicated: I have one set of preferences which need to have at least one common element and another set of preferences which may not have a common element. In a later step I also want to restrict this to documents (users) within a certain geographical distance.
Currently I have this code working in my map function, but I would prefer to separate this into either query params as supported by mongoid or a javascript function. All my attempts to solve this failed since the code is either ignored or raises an error.
I did a couple of tests.
[results deleted, see below]
I'm using ruby 1.9.2, mongodb 1.6.5-x86_64, and the mongoid 2.0.0.beta.20, mongo 1.1.5 and bson 1.1.5 gems on MacOS.
What am I doing wrong?
Thanks in advance.
More Tests (problem partly solved):
User.where(:name.in => ["Arno", "Bernd", "Claudia"])
works, however when using mapreduce like this
mapreduce(..., :query => { :name.in => ['Arno', 'Bernd', 'Claudia'] })
results in the bson error serialize: keys must be strings or symbols (TypeError) mentioned above.
Replacing :name.in with 'name.in' or 'name.$in' makes the query return no results (guess this is passed as is to mongodb).
However
mapreduce(..., :query => { :name => { '$in' => ['Arno', 'Bernd', 'Claudia'] } })
works, but I didn't have any success with my geospatial query attempts, no matter how I wrote the expression.
mapreduce(..., :query => {:location => { "$near" => [ 13, 52, 1 ] } })
results in this error_message: Database command 'mapreduce' failed: {"assertion"=>"manual matcher config not allowed",....
If anyone could give me an idea how to write a geospatial query using near or within and working with mapreduce I would be very happy. (I didn't play with sets yet, see above).