How does MongoDB sort/compare objects - mongodb

Couldn't find any clear documentation on how does MongoDB compare/sort complex objects. I've tried some examples and found out property order does matter and property names also matter
Examples:-
Order matter
{“name”: {“first”: “A”, “last”: “B”}} != {“name”: {“last”: “B”, “first”: “A”}}
Values matter
{“name”: {“first”: “A”}} < {“name”: {“first”: “B”}}
property names matter
{“name”: {“**f**irst”: “A”}} < {“name”: {“**g**irst”: “A”}}
So wondering how exactly does that work, I'm sure stuff like missing properties would also affect this.

If you sort on embedded object fields like name, the sort comparisons are done using at the binary representation (BSON object) level, which isn't very useful.
What you typically want to do instead is identity the specific fields within those objects using dot notation, putting them in the order you want:
// Sort on last name, and then first name
db.test.find().sort({'name.last': 1, 'name.first': 1})

Related

Gremlin: Is there a way to find the character based on the index of a string?

I have vertex "office" and property "name" on OrientDB. I want to find the offices, by name, where the name does not have a "-" as the third character of the string. I imagine this would require some java code within the gremlin query.This is my best attempt, but it is resulting in office names that do in fact have a "-" as their third character.
g.V().hasLabel('office')
.where(values('name').map{it.get().charAt(2)}.is(neq('-')))
.project('Office Name')
.by(values('name'))
Since Gremlin doesn't support String operations (like split, charAt, etc.), your only chance is a lambda. Seems like you figured that out already, but your solution looks too overcomplicated to me. You can use something much simpler, like:
g.V().hasLabel('office').
has('name', filter {it.get()[2] != '-'}).
project('Office Name').
by('name')
However, note, that this filter will throw an exception if the office namer has less than 3 characters. Thus, you should better check that the String is long enough:
g.V().hasLabel('office').
has('name', filter {it.get().length() > 2 && it.get()[2] != '-'}).
project('Office Name').
by('name')
...or use RegEx pattern matching (which is pretty nice and easy in Groovy):
g.V().hasLabel('office').
has('name', filter {it.get() ==~ /.{2}-.*/}).
project('Office Name').
by('name')
The main reason why your traversal didn't work though, is that charAt returns a Character which is then compared to the String -, hence every office name will pass the neq filter.

AEM CQ5 Query Builder: How to get result by searching for 2 different values in same property?

I want to get result matches with all nodes contains property 'abc' value as 'xyz' or 'pqr'.
I am trying in below ways:
http://localhost:4502/bin/querybuilder.json?path=/content/campaigns/asd&property=abc&property.1_value=/%xyz/%&property.2_value=/%pqr/%property.operation=like&p.limit=-1&orderby:path
http://localhost:4502/bin/querybuilder.json?path=/content/campaigns/asd&property=abc&property.1_value=/%xyz/%&property.2_value=/%pqr/%&property.1_operation=like&property.2_operation=like&p.limit=-1&orderby:path
http://localhost:4502/bin/querybuilder.json?path=/content/campaigns/asd&1_property=abc&1_property.1_value=/%xyz/%&1_property.1_operation=like&2_property=abc&1_property.1_value=/%xyz/%&2_property.1_operation=like&p.limit=-1&orderby:path
But none of them served my purpose. Any thing that I am missing in this?
The query looks right and as such should work. However if it is just xyz or pqr you would like to match in the query, you may not need the / in the values.
For eg.
path=/content/campaigns/asd
path.self=true //In order to include the current path as well for searching
property=abc
property.1_value=%xyz%
property.2_value=%abc%
property.operation=like
p.limit=-1
Possible things which you can check
Check if the path that you are trying to search contains the desired nodes/properties.
Check if the property name that you are using is right.
If you want to match exact values, you can avoid using the like operator and remove the wild cards from the values.
You can actually use the 'OR' operator in your query to combine two or more values of a property.
For example in the query debug interface : http:///libs/cq/search/content/querydebug.html
path=/content/campaigns/asd
property=PROPERTY1
property.1_value=VALUE1
property.2_value=VALUE2
property.operation=OR
p.limit=-1
It worked with below query:
http://localhost:4502/bin/querybuilder.json?orderby=path
&p.limit=-1
&path=/content/campaigns
&property=jcr:content/par/nodeName/xyz
&property.1_value=pqr
&property.2_value=%abc%
&property.operation=like
&type=cq:Page
Note: property name should be fully specified form the type of node we are expecting.
Ex: jcr:content/par/nodeName/xyz above instead of just xyz

MongoDB: Using *NOT-dot* notation in sort

I'm having an issue with the Mongo sort on nested collection and Google search didn't help:
Dot notation works (returns first element from sorted collection):
db.myCollection.find().sort({ 'comments.Comment' : -1 })[0]
Array (Not-dot) notation doesn't work (always returns first element from un-sorted collection):
db.myCollection.find().sort({ "comments['Comment']" : -1 })[0]
For some business reasons I would like my app to be dynamic and handle spaces/pluses/and few more un-standard characters as the keys in the documents,
So far I was ok with it but sort always returns first (unordered) result if it can't understand the key which I want to sort on.
Simply put:
"For some business reasons I would like my app to be dynamic and handle spaces/pluses/and few more un-standard characters as the keys in the documents"
Yeah, well bad luck it's not valid JSON notation, it may be JavaScript notation but that doesn't mean it's valid JSON. And the BSON spec derives from this fact.
You have dot (.) notation and that is it. So basically your condition is parsed as "invalid" and is ignored, hence no sorting is done how you expect.
Feel free to raise a JIRA issue with MongoDB if you believe this is important.

JQuery Wildcard for using atttributes in selectors

I've research this topic extensibly and I'm asking as a last resort before assuming that there is no wildcard for what I want to do.
I need to pull up all the text input elements from the document and add it to an array. However, I only want to add the input elements that have an id.
I know you can use the \S* wildcard when using an id selector such as $(#\S*), however I can't use this because I need to filter the results by text type only as well, so I searching by attribute.
I currently have this:
values_inputs = $("input[type='text'][id^='a']");
This works how I want it to but it brings back only the text input elements that start with an 'a'. I want to get all the text input elements with an 'id' of anything.
I can't use:
values_inputs = $("input[type='text'][id^='']"); //or
values_inputs = $("input[type='text'][id^='*']"); //or
values_inputs = $("input[type='text'][id^='\\S*']"); //or
values_inputs = $("input[type='text'][id^=\\S*]");
//I either get no values returned or a syntax error for these
I guess I'm just looking for the equivalent of * in SQL for JQuery attribute selectors.
Is there no such thing, or am I just approaching this problem the wrong way?
Actually, it's quite simple:
var values_inputs = $("input[type=text][id]");
Your logic is a bit ambiguous. I believe you don't want elements with any id, but rather elements where id does not equal an empty string. Use this.
values_inputs = $("input[type='text']")
.filter(function() {
return this.id != '';
});
Try changing your selector to:
$("input[type='text'][id]")
I figured out another way to use wild cards very simply. This helped me a lot so I thought I'd share it.
You can use attribute wildcards in the selectors in the following way to emulate the use of '*'. Let's say you have dynamically generated form in which elements are created with the same naming convention except for dynamically changing digits representing the index:
id='part_x_name' //where x represents a digit
If you want to retrieve only the text input ones that have certain parts of the id name and element type you can do the following:
var inputs = $("input[type='text'][id^='part_'][id$='_name']");
and voila, it will retrieve all the text input elements that have "part_" in the beginning of the id string and "_name" at the end of the string. If you have something like
id='part_x_name_y' // again x and y representing digits
you could do:
var inputs = $("input[type='text'][id^='part_'][id*='_name_']"); //the *= operator means that it will retrieve this part of the string from anywhere where it appears in the string.
Depending on what the names of other id's are it may start to get a little trickier if other element id's have similar naming conventions in your document. You may have to get a little more creative in specifying your wildcards. In most common cases this will be enough to get what you need.

Asp.Net MVC 2: How exactly does a view model bind back to the model upon post back?

Sorry for the length, but a picture is worth 1000 words:
In ASP.NET MVC 2, the input form field "name" attribute must contain exactly the syntax below that you would use to reference the object in C# in order to bind it back to the object upon post back. That said, if you have an object like the following where it contains multiple Orders having multiple OrderLines, the names would look and work well like this (case sensitive):
This works:
Order[0].id
Order[0].orderDate
Order[0].Customer.name
Order[0].Customer.Address
Order[0].OrderLine[0].itemID // first order line
Order[0].OrderLine[0].description
Order[0].OrderLine[0].qty
Order[0].OrderLine[0].price
Order[0].OrderLine[1].itemID // second order line, same names
Order[0].OrderLine[1].description
Order[0].OrderLine[1].qty
Order[0].OrderLine[1].price
However we want to add order lines and remove order lines at the client browser. Apparently, the indexes must start at zero and contain every consecutive index number to N.
The black belt ninja Phil Haack's blog entry here explains how to remove the [0] index, have duplicate names, and let MVC auto-enumerate duplicate names with the [0] notation. However, I have failed to get this to bind back using a nested object:
This fails:
Order.id // Duplicate names should enumerate at 0 .. N
Order.orderDate
Order.Customer.name
Order.Customer.Address
Order.OrderLine.itemID // And likewise for nested properties?
Order.OrderLine.description
Order.OrderLine.qty
Order.OrderLine.price
Order.OrderLine.itemID
Order.OrderLine.description
Order.OrderLine.qty
Order.OrderLine.price
I haven't found any advice out there yet that describes how this works for binding back nested ViewModels on post. Any links to existing code examples or strict examples on the exact names necessary to do nested binding with ILists?
Steve Sanderson has code that does this sort of thing here, but we cannot seem to get this to bind back to nested objects. Anything not having the [0]..[n] AND being consecutive in numbering simply drops off of the return object.
Any ideas?
We found a work around, by using the following:
Html.EditorFor(m => m, "ViewNameToUse", "FieldPrefix")
Where FieldPrefix is the "object[0]". This is hardly ideal, but it certainly works pretty well. It's simple and elegant.