I'm new to linq. here is the scenario i need to write query for.I have a "Candidate" table with a varchar property "Skill"I have the table OR-mapped with LINQ to SQL on dbml file. Now I want to write linq query that:Selects all Candidates that have skill containing any of the keywords from ("asp.net","php","java")
View 1 RepliesI'm constructing a query using linq, but I'm having trouble using a collection, i.e. where field in database = anything in the collection.
Below is an example of what I mean:
dim keywords as string ="test,test2,test3,cats,dogs,frogs"
Dim getKeywords = (From cp In myDataContext.pages
Where cp.pageKeywords = currentPageKeywords.Split(",")
The aim of the above code is to return all records where the "pageKeywords" field contains 1st keyword, or 2nd keyword, or 3rd keyword etc.
I'm new to LINQ and have a problem with my query not showing me the Table Collection. I manually created my Cart class and specified the table attributes on each property (works fine for inserting records via LINQ see below). DataContext dc = new DataContext(Conn);
var q = (from c in dc.NOTABLES?? where ((c.UserID == userID)) orderby c.CreateDateTime Based on examples I would expect to see dc.Cart But I don't, so I tried to access it via dc.GetTable<Cart>() which at least gets me data but doesn't seem to convert the rows to my Cart object since this:
foreach (var cart in q) Log.Info("UserID: " + cart.UserID + " CartID: " + cart.ID.ToString());
blows up with a "Specified Cast is Not Valid" exception.
No Problem Inserting Also, I had no problem inserting data into the database:
DataContext dc = new DataContext(Conn);
Table<Cart> Carts = dc.GetTable<Cart>();
Cart aCart = new Cart();
aCart.UserID = userId;
aCart.Description = description;
aCart.CreateDateTime = System.DateTime.Now;
aCart.UpdateDateTime = System.DateTime.Now;
Carts.InsertOnSubmit(aCart);
Carts.Context.SubmitChanges();
I have a really weird problem. It actually made me restart the computer.
View 1 RepliesWhat is difference between select { } and select new {} In Linq Query
View 3 RepliesI am writing a linq query to select a blogpost,
[code]....
The blogpost i am testing got 3 tags attached to it. The table structure is:
(table)BlogPost -> (table)BlogPostTags <- (table)Tags
So the BlogPostTags table only contains 2 fields, BlogPostID and TagID.
When i run the query above i get 3 results back. Same blogpost 3 times but with 1 tag in each. It should return 1 post with 3 tags. The problem lies in the Tags query above.
I am using LINQ-to-Entities and here is my query
public void SomeFunction(string searchField)
{
var data = from a in dx.SomeTable where [code]...
Now if I had to use the value of the parameter "searchField" as the property to be selected in the where clause then how do I do it ?
i.e I want to assign the value of the parameter "searchField" to the property I am checking in the where clause.
So ... the value of "SomeProperty" in a.SomeProperty must be the value of "searchField". How to do this ?
PS : I dont want a.SomeProperty=searchField. What I want is "SomeProperty" itself to be replaced by the value of "searchField" and then , this has to be checked to see if its equal to 270.
I'm building an ASP.NET MVC site that uses LINQ to SQL. In my search method that has some required and some optional parameters, I want to build a LINQ query while testing for the existence of those optional parameters.
Here's what I'm currently thinking:
using(var db = new DBDataContext())
{
IQueryable<Listing> query = null;
//Handle required parameter
query = db.Listings.Where(l => l.Lat >= form.bounds.extent1.latitude && l.Lat <= form.bounds.extent2.latitude);
//Handle optional parameter
if (numStars != null)
query = query.Where(l => l.Stars == (int)numStars);
//Other parameters...
//Execute query (does this happen here?)
var result = query.ToList();
//Process query...
Will this implementation "bundle" the where clauses and then execute the bundled query? If not, how should I implement this feature?
My application includes BUILDING table with columns BUILDING_ID, NAME, TOWN_ID, I run the LINQ query listed below and need to append two letters to buildings.NAME based on TOWN_ID. I assume that I need to place an "if" or "select" statement inside the query but I can not figure out how to do that,
[Code]....
I will declarate a attribute, but it gives me an error
This query works fine and returns 1 record from type int:
SELECT TOP 1 DataObjectVersionID
FROM tblDataObjectVersionPropertyValueText
WHERE PropValue like CAST('00010281' AS ntext)
ORDER BY DataObjectVersionID DESC
And when I will declarate a attribute/parameter it gives me an error:
DECLARE @dataObjectVersionId INT
SET @dataObjectVersionId = SELECT TOP 1 DataObjectVersionID
FROM tblDataObjectVersionPropertyValueText
WHERE PropValue like CAST('00010281' AS ntext)
ORDER BY DataObjectVersionID DESC
Error message:
Msg 156, Level 15, State 1, Line 2
Incorrect syntax near the keyword 'SELECT'.
I have 2 Tables , OrderDetails and Requests In my LINQ to SQL dbml file. OrderDetailsID is a foreign key in Requests Table. I want to write the query to get the sum of UnitCost from OrderDetails based on OrderId. And If there is a row in Requests Table for each OrderDetailsID, and the Requests.Last.RequestType="Refund" I want to reduce the total refund amount from the main sum otherwise If there is no row based on OrderDetailsID, add to sum. Here is the way I implement that. I am looking to prevent using "For each".
iRefund = (From od1 In dc.OrderDetails _
Where od1.OrderID =1 _
Select od1.UnitCost).Sum
Dim objOrderDetails = (From od1 In dc.OrderDetails _
Where od1.OrderID =1 _
Select od1)
For Each OrderDetail As ORM.Entities.OrderDetail In objOrderDetails
If Not OrderDetail.Requests Is Nothing Then
IF OrderDetail.Requests.Last.RequestType="Refund" Then
iRefund -= OrderDetail.UnitCost
End If
End If
Next
how do i create linq query and asign that query to as data source to datalist on default.aspx.cs page
View 3 Replies[Code]....
using System;
using System.Collections.Generic;
using System.Linq;
using System.Data.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace find.Admin
{
public partial
class WebForm1 : System.Web.UI.Page
{
private
class servicetimeofday
{
public int servicetimeofdayid {
get; set; }
public int serviceid {
get; set; }
public int timeofdayid {
get; set; }
}
protected void Page_Load(object sender,
EventArgs e
{
List<servicetimeofday> servicetimesofday =
new
List<servicetimeofday>
{
new servicetimeofday() { servicetimeofdayid = 1, serviceid = 1, timeofdayid = 1 },
new servicetimeofday() { servicetimeofdayid = 2, serviceid = 1, timeofdayid = 2 },
new servicetimeofday() { servicetimeofdayid = 3, serviceid = 2, timeofdayid = 1 },
new servicetimeofday() { servicetimeofdayid = 4, serviceid = 2, timeofdayid = 3 }
};
GridView2.DataSource = servicetimesofday;
GridView2.DataBind();
var itemstocheck = from
servicetimeofday in servicetimesofday
where servicetimeofday.serviceid == 2
select ne
servicetimeofday.timeofdayid
};
GridView3.DataSource = itemstocheck;
GridView3.DataBind();
foreach (var timeofdayid
in itemstocheck)
{
foreach (ListItem i
in CheckBoxList2.Items)
{
if (i.Value == timeofdayid.ToString())
{ i.Selected =
true; }
}
}
}
}
}
I have a basic CMS which I'm adding to a site to display some downloads organised into groups. I have two tables, one for the groups and one for the downloads. I'm using a repeated to display the groups with another repeater inside to display the children. This works perfectly.
However some of my download groups may not have any downloads related to them and I'd like to handle this by filter the groups so that only those with a relate download record(s) are shown.
I'm trying to do this with the query which populates the top repeater based on some ideas I read but I must be going wrong with the syntax.
Here is what I'm using to try and only select downloads groups which have downloads linked to them by the download group ID.
[Code]....
Can anyone offer any thoughts on how I should construct the query to perform this?
Is yield keyword is Statement keyword or Contextual Keyword?
Because in MSDN yield keyword is mentioned in both type of Keywords so i'm little bit confused in this.
I'm trying to pass a list of items from a LINQ query to a View, but I'm having trouble figuring out how to resolve a type issue. Here's the error:
The model item passed into the dictionary is of type 'System.Data.Linq.DataQuery`1[Project.Models.Diagnostic]' but this dictionary requires a model item of type 'Project.Models.Diagnostic'.
The issue seems to originate with this code from my Controller:
[Code]....
I tried changing the IQueryable<Diagnostic> to var and got the same error. Also played around with something like:
[Code]....
But then VS2008 says that diagnostics could never be null, and that's may not the best (or even valid) way to do it.
I'm looking to translate an SQL query into linq
INNER JOIN Usrs ON
SAQ.UserId =
Usrs.UserId AND Scan.UserId =
Users.UserId
I'm not sure how to include the "AND" in the LINQ statement.
I have been trying to design a form, which uses a view model that contains an object array. I want to set up this form so that when the submit button is clicked, all the members of the array are updated. Here is my code:
The class definition of the array element:
[Code]....
The problem is that when I clicked the submit button, none of the luSubject objects in the array Subjects got updated. But if I set up some initial values for the members of the luSubject objects, for instance, set the Name field to be "Maths" in the constructor of luSubject class, then it got displayed on the text box when the form page was loaded. This suggests that this form could display the data in the array, but cannot update it.
I'm trying to "move" a LinqDataSource control to code behind to better control the query parameters. Problem I'm having is how does the "It" keyword translate to Linq To SQL syntax (not sure if I'm getting the terminology right here, but I think you get my meaning).
Control Markup:
[Code]....
Query:
[Code]....
I am using ASP.net to retrieve data from a Lotus notes DB using OLEDB connection. I use a ADOrecordset to read the values. When I open the ADo connection, I would like to store each record being read in a custom object and thereby create a collection of custom objects as ADO connection times out when kept open for long.
I then need to iterate throught the collection of custom objects to retrieve the values.
I am using asp.net 2010
I want to be able to update a model and all its collections of child objects in the same view. I have been referred to these examples: http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx and http://blog.stevensanderson.com/2010/01/28/editing-a-variable-length-list-aspnet-mvc-2-style/ .
For example, I have an object Consultant, that has a collection of "WorkExperiences". All this is in an Entity Framework model. In the view, the simple properties of the Consultant object is no problem, but the collection I cannot get a textbox to show up for. I tried following the examples in the links above, but it doesn't work. The problem is, in those examples the model is just a list (not an object with a child list property). And also, the model again is an EF model. And for some reason that doesn't seem to work as in those examples.
[Code]....
This stuff with the EditorTemplate works fine in Phil Haack's sample project, which I downloaded to try, but here, with the EF model or whatever the problem is, I don't get any textbox at all. The table in the view is just there as a test, because in the table I do get the rows for WorkExperiences, whether I add an empty WorkExperience object or fill out its properties doesn't matter, the rows show up for each object. But again, no textbox...
Is it possible to have ON and WHERE , both keyword using Joins in a single query
View 6 Repliesi am developing a web site in Asp.Net using Visual Studio 2008.i want to know that how can i search a keyword that will be entered by the user, i want the key word should be searched in complete database(all the tables)using a single query.I am using sql database. how can the keyword be searched using like parameter...
View 1 RepliesI am playing with Asp.net MVC 3, I was wondering how do you acheive a collection rendering in the view when the collection is made of 'real world' objects. Let's say I have a collection of client, each client
may have an address and an adress may have a country.
When I write the following code it crashs if one of the client has a null address (or a null country). Object reference not set to an instance of an object.
[code]...
I am binding a datalist to some table 0 of a dataset from the database. When I check the number of rows in the dataset table 0 it's coming as 129 but when I check the count of the datalist items(using Datalist_Name.Items.Count) inside the datalist item created event I am getting a maximum count of 128.Due, to this I am unable to assign values to the last label control(last as in the last row) present inside the datalist dynamically. I am not sure where I am going wrong. I even tried to replicate the same code inside the ItemDataBound event but even then I am getting the same error.
View 5 Replies