C# - Linq To SQL Mplementation Of Query Operators Except The Contains() Operator?
Mar 26, 2010
I have a local collection of record Id's (integers).I need to retrieve records that have every one of their child records' ids in that local collection.
Here is my query:
public List<int> OwnerIds { get; private set; }
...
filteredPatches = from p in filteredPatches
where OwnerIds.All(o => p.PatchesOwners.Select(x => x.OwnerId).Contains(o))
select p;
[code]...
I am getting this error:Local sequence cannot be used in Linq to SQL mplementation of query operators except the Contains() operator.I understand that.All() isn't supported by Linq to SQL, but is there a way to do what I am trying to do?
I'm creating a repository and service layer in my app, and my repo has a very simple function
Public Function GetRegions() As IQueryable(Of Region) Implements IRegionRepository.GetRegions Dim region = (From r In dc.Regions Select r) Return region.AsQueryable End Function
Now in my Service layer I've got a function like this
Public Function GetRegionById(ByVal id As Integer) As Region Implements IRegionService.GetRegionById Return _RegionRepository.GetRegions().Where(Function(r) r.ID = id).FirstOrDefault End Function
But i can't figure out how to add And r.isActive = True
i am looking for a solution using IN-Operator with LINQ TO SQL. I have found many examples after searching but no exemple which is using a Textbox.In my Textbox i put my ids 2,4,6,7,9 and after clicking the button, it have to show me my Records. But it does not.The error-message shwos me a wrong format.Ausnahmedetails: System.FormatException: Die Eingabezeichenfolge hat das falsche Format.
Zeile 5: Dim result As String = "" Zeile 6: Dim intText As String = Me.tbKursid.Text >>>>>>>> Zeile 7: Dim myText() As Integer = {Convert.ToInt32(intText)} Zeile 8: Dim db As New seminarDataContext Zeile 9: Dim daten = From c In db.vSchluessel _
If i use Dim myText() As Integer = {1,4,5,6} then it runs without problems. What is wrong?
im using MS-Access database, i tried to add some data to the database from C#. the column datatype is Memo.
From front-end, the user type some text on HTML editor that content to be add to this column, if i enter minimal text then data is adding fine but, if enter 2 or 3page content then im getting error as
I have a Excel user application which has a user form (named 'Registo') that displays criteria and an image that has been entered in it's corresponding spreadsheet. This works the way it should. There's also the ability to search the spreadsheet via a form (by clicking 'Pesquisar' button) this opens a search form. However, I having a bit of a problem with it. When I try to search for something it basically doesn't do anything at all. It just sits there. So I tried to debug it and I think I'm having a problem with either the JET db engine or somethign with teh query or maybe I don't have the correct reference.
Microsoft OLE DB Provider for ODBC Drivers (0x80040E14) [Microsoft][ODBC Microsoft Access Driver] Syntax error (missing operator) in query expression 'id='. /bioskop/pesan.asp, line 13
i am new to asp.net i am trying to develop an asp.net application i,e registration form in asp.net as user interface and ms access 2007 database as backend.i am trying to make aconnection to ms access 2007 db and save the data entered by the user in asp.net application.
i have saved my access db 2007 file in 'D drive' and my code in application is:
The issue is two fold in my ASP.NET Web Application. I need to use a custom Distinct() via LINQ to SQL, and then assign thevar as a DataSource to a GridView.
If I use the custom Distinct that implements IEqualityComparer,I get "Unsupported overload used for query operator 'Distinct'" exception. but if i somehow get past this, i get "The data source does not support server-side data paging" exception on GridView.DataBind(). here is the code:
[Code]....
And here is the IEqualityComparer:
[Code]....
With this code I get Unsupported overload used for query operator 'Distinct'. BUT! if I change the code to
[Code]....
, I get System.NotSupportedException: The data source does not support server-side data paging
I'm using Visual Studio 2008 Query Builder and am trying to pass a value to a parameter that uses the IN OPERATOR.Here is my sql from qb:
SELECT COURSE_TITLE, INSTR_NAME, ADMIN_UNIT FROM vwHRIC_EC_ContractSummary WHERE (ADMIN_UNIT IN (@ADMIN_UNIT))
The trouble I am having is that if the parameter @ADMIN_UNIT contains more than one value such as (8X, CV) that the query doesn't return any data. If I run the same query with only one value such as (8X) it works fine.I have tried different formats like (8X, CV), ('8X', 'CV'), (8X; CV) but none have worked.I ran this same query in SQL Server Management Studio and and it returns data no problem but can't get it to work in Query Builder for my aspx application.Does anyone have any experience with this problem and how did you correct it?
I'm having problem in inserting text from a textbox in which user write or copy some text which may contain special characters ( " , . ) etc. If there is any special character it get conflict with CommandText Syntax and generates error in inserting. I want to insert all these characters. How could i do it?
I've build a linq query.But i want a random selection so its not always ID : 1,2,3,4,5,6 How can i randomize this var? I like to bind it to a repeater.//TagCloud:
Random rand = new Random(); var tc1 = from i in JumpTide.cms.menu.GetMenuItems(32) select new
I am facing a big problem with simple linq query.. I am using EF 4.0..
I am trying to take all the records from a table using a linq query:
var result = context.tablename.select(x=>x);
This results in less rows than the normal sql query which is select * from tablename;
This table has more than 5 tables as child objects (foreign key relations: one to one and one to many etc)..
This result variable after executing that linq statement returns records with all child object values without doing a include statement.. I don't know is it a default behavior of EF 4.0 . I tried this statement in linqpad also..but there is no use... But interesting thing is if I do a join on the same table with another one table is working same is sql inner join and count is same..but I don't know why is it acting differently with that table only.. Is it doing inner joins with all child tables before returning the all records of that parent table?
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.
What is the preferred way to handle this? Delegates? I have a dropdown box of comparison operators = <, <=, > , >=, == which is used to set up a filter. The filter expression is exactly the same for every case other than the operator. I can do it through a switch, but I am sure there is a one liner that can handle to entire problem. Just not sure what it is?
I have a web app for our golf club. When I compute handicap index for each golfer, I have to select the most recent scores and then a subset of those scores depending on how many rounds of golf the golfer has played. All the scores are entered into a single SQL Express table called "Rounds". Verbally, this is what I'm trying to do:
1) select the twenty most recent golf scores (sort on date descending, "take(20)") [if less than 20 records, then select all available];
2) for this set of records, select the 10 lowest scores (or smaller number if golfer has less than 20 rounds);
3) compute the average round differential for the subset of records, etc. to calculate handicap index (this step is working ok...)
My current VB code has this LINQ query (which is flawed -- it selects the lowest handicap differential scores of ALL records for the filtered user):
[Code]....
How do I modify this query to accomplish items 1) & 2) above? It seems this should be simple, but my experience with queries is still limited.
List<string> EmailId= { ....} Now I have a db table Users. I need to select all users whose email exist in the above list. In sql we could write "where emailid in ('email1', email2' ,...)"
how to do this in linq to sqlquerable<Users> existingUsers = Users.getTable().where (u=>u.emailaddress in EmailId). I want to do some thing similar
I need to figure out how to express this in linq to sql:I have one or more records that contain what is essentially a wildcard sql parameter, like '100_-___-2', which should match 100[any 1 char]-[any 1 char][any 1 char][any 1 char]-2, for example. Each login will have one or more of these 'datamasks' associated with it.I need to write a query in linq to sql that does something like:
select * from something where fieldA = 'someValue' or fieldB = 'someValue'
so far, simple, but I also need to restrict the returned records to only those that match the user's 'datamasks'. I'm not sure exactly how to translate this to linq to sql... here is what a working query *without* the datamasks part looks like:
[Code]....
I need to tack on the datamasks part... can I do it right there in the same statement? or do I need to do a foreach loop on the datamasks records and append a new && condition for each one? hmmm... just thought of that as I was writing this.. I'll try that out. But I'm posting this anyway for more input... I guess that would look something like:
