I just want to remove one record in table "Meta" for example PasswordInfo
I tried this code:
var data = _mednoteDb.GetCollection(Users).FindOne(...);//specific record
data.Remove("PasswordInfo");
but it didin't work.
Code
I am not a mongodb superexpert, but depending on the format of your data you might want to be using one or another of the mongodb operator functions.
$pull is the operator for deleting element from an array property of a document, documentation here.
$unset is the operator for deleting subdocument from a document, documentation here.
There are a bunch of examples already on stackoverflow, if you don't find what you are search looking for, I can point you in some specific directions.
Related
my following problem is, that I have a List of Items and want to index those with elasticsearch. I have a running elasticsearch instance, and this instance has an index called "default".
So I'm running following code:
var items = GetAListOfItem();
var response = Client.IndexMany(items);
I also tried it with Client.IndexManyAsync(items). But that didn't do anything.
Only 1 Item of this List gets indexed. Nothing more. I think its the last item, which got indexed.
I thought it could be a thing with IEnumerable and multiple enumerations, but i parsed it as a List<Item>.
Another Question would be about the best practice with Elasticsearch. Is it common to use a Index per Model. So if I'm gathering data from for example Exchange and another system, I would do 2 indeces?
ExchangeIndex
OtherSystemIndex
Thank you for your help.
Update: I saw that my Client.Index does all those calls succesful, but all those objects got the same ID from NEST. Normally she had to increment by herself, isnt it?
Update 2: I fixed the Indexing Problem. I had setup an empty ID-Field.
But still have the question mit best practive about Elasticsearch.
If you are uploading all the data with the same id, it will not increment the id, that will update the record with that id and you will have only one record, so you can upload the data without an id or give wherever unique id to identified the records.
The other common problem is that your records have not the same mapping that you give for the index.
About the other question, in the indexes, you store the information that is relevant for you, even if that have content from many models, the only thing that you have to avoid is mix information, if you have an index about server logs dont mix it with user activities for example.
I made a form that basically displays information about different vendors from an XML file that I was given. The XML file is retrieved from a class that I created, called VendorsDB.cs. On my form, I have a Previous and Next button that I want to display the next vendor or the previous vendor (Vendor1, Vendor2...) but I have no idea what method to use. I know I have to use a loop but I'm not sure as to how to code the loop. I've just started programming with C# so I'm really lost. Any help would be greatly appreciated!
Your question is missing alot of information, but what im seeing is that you need to do some work with XML.
I suggest you look into Linq To XML which enabled you to query tags and attributes with query syntax.
A very simple query good look like this:
// Load the xml from the specified path
var xml = XDocument.Load(#"LocationOfXml");
// Query the first element with a "MyXmlTag" as name
var someAttribute = xml.Descendants().FirstOrDefault(x => x.Name == "MyXmlTag");
The query language is far richer than this simple query. Read up and im sure you'll be able to get it working asap.
I'm currently writing a function to save and read data to/from and XML document through
LINQ. Currently I can write the document just fine, but if I go to add data to an existing item, it simply adds a new item. My goal is to create an address book type system (yes I know there's 1000 out there, it's just a learning project for myself) and I've tried ini and basic text but it seems that XML is the best way to go short of using a local DB like sql. Currently I have:
XDocument doc = XDocument.Load(#"C:\TextXML.xml");
var data = new XElement("Entry",
new XElement("Name", textBox1.Text),
new XElement("Address", richTextBox2.Text),
new XElement("Comments", richTextBox1.Text));
doc.Element("Contacts").Add(data);
doc.Save(#"C:\TextXML.xml");
I searched SO and can't seem to find how to append/replace.
Now this saves everything properly, even when I add to the document, but if I want to update an entry I'm not sure how to without creating a new "Entry" nor am have I gotten the knack of removing one. (I'm somewhat new to C# still and self-taught so pardon anything obvious I've overlooked.)
My second issues revolves around loading the information into textboxes.
I'm able to load a list of Entry names into a listbox, but when I go to open the information from that entry I'm not sure how to properly get the nested info.
With the example above I'd need something similar to the following:
XDocument doc = XDocument.Load(#"C:\TextXML.xml");
boxName.Text = The name from the SelectedItem of the list box.
boxAddress.Text = The address child of the element named above etc.
Each method I've tried I wind up with a null reference exception, which tells me I'm not pointing to the right thing, but I'm not sure how to get to those things properly.
I've also tried creating a string and var of the SelectedItem from the list box to help with the naming, and using ToString methods, but still can't figure it out.
For replacing values, there are several functions you can use in XElement:
Value (property with a public setter)
SetValue()
SetElementValue()
SetAttributeValue()
ReplaceWith()
ReplaceNodes()
For example, if you wanted to replace the value in Name:
data.Element("Name").SetValue("NewValue");
or
data.Element("Name").Value = "NewValue";
For loading, once you have the XElement node you desire, then it's as simple as doing
xelement.Value
Or if it's an attribute:
xelement.Attribute("AttributeName").Value
Using your code as an example:
boxName.Text = doc.Element("Entry").Element("Name").Value;
Edit to address comment:
If I'm reading your comment right, you're wanting to extract the Name/Address/etc. data from all the nodes within the Contacts main node?
If so, then you would probably want something like this:
boxName.Text = string.Join(",", doc.Elements("Entry").Select(x => x.Element("Name").Value));
This will give you a single string that has all the names in all Entries separated by a comma. Just change "Name" to "Address" to do the same for addresses.
I'd suggest doing a search for Linq to XML for finding more information about how to use this parsing.
I have a grid and I need to support full text search. I need to support search not only by start with and end with, but I need to support search by the part of word. For example if I have "MyWord", I need that search will found by the part of "wor". If I try to use string.contains() I get the following error:
Contains is not supported, doing a substring match over a text field is a very slow operation, and is not allowed using the Linq API.
The recommended method is to use full text search (mark the field as Analyzed and use the Search() method to query it.
If I build raven db index and mark field as Analyzed, contains is not working. It works with StartWith() and EndWith(), but not with contains. Using .Search() I'm getting the same results. Another option is to use lucene syntax:
.Where("Name:*partOfWord*")
and it works fine, but I don't want to combine linq with lucene syntax and I want to solve it using raven db indexes.
Have you any ideas how to implement full text search for raven db using indexes?
You want to be using an NGram analyzer, as described here. It's an analyzer you can add to your RavenDB server by dropping its DLL in the Analyzers folder.
You really don't want to do any *substr Lucene queries ("ending with" clauses, that is), because the performance is terrible. The inconsistency in coding style is a lesser problem.
I use this query to search for persons full names by just typing a part of the name. It is recommended to set a minimum length of search string.
.Search(x => x.Name, "word to search" + "*", escapeQueryOptions: EscapeQueryOptions.AllowPostfixWildcard)
I'm taking over a project so I'm still learning this. The project uses Lucence.NET. I also have no idea if this piece of functionality is correct or not. Anyway, I am instantiating:
var writer = new IndexWriter(directory, analyzer, false);
For specific documents, I'm calling:
writer.DeleteDocuments(new Term(...));
In the end, I'm calling the usual writer.Optimize(), writer.Commit(), and writer.Close().
The field in the Term object is a Guid, converted to a string (.ToString("D")), and is stored in the document, using Field.Store.YES, and Field.Index.NO.
However, with these settings, I cannot seem to delete these documents. The goal is to delete, then add the updated versions, so I'm getting duplicates of the same document. I can provide more code/explanation if needed. Any ideas? Thanks.
The field must be indexed. If a field is not indexed, its terms will not show up in enumeration.
I don't think there is anything wrong with how you are handling the writer.
It sounds as if the term you are passing to DeleteDocuments is not returning any documents. Have you tried to do a query using the same term to see if it returns any results?
Also, if your goal is to simple recreate the document, you can call UpdateDocument:
// Updates a document by first deleting the document(s) containing term and
// then adding the new document. The delete and then add are atomic as seen
// by a reader on the same index (flush may happen only after the add). NOTE:
// if this method hits an OutOfMemoryError you should immediately close the
// writer. See above for details.
You may also want to check out SimpleLucene (http://simplelucene.codeplex.com) - it makes it a bit easier to do basic Lucene tasks.
[Update]
Not sure how I missed it but #Shashikant Kore is correct, you need to make sure the field is indexed otherwise your term query will not return anything.