Hi guys I need to rewrite the sql query below using Linq to entity. Unfortunately I don't have a lot of experience of using Linq.
With TempTableName AS
(SELECT [ColumnName],
[ColumnName2],
[ColumnName3],
[ColumnName4],
ROW_NUMBER() OVER (order by ColumnName desc) as RowNumber from TableName )
SELECT
[ColumnName],
[ColumnName2],
[ColumnName3],
[ColumnName4]
FROM TempTableName WHERE ROWNUMBER
Between 10 and 100
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.
Need to figure out the correct way to do a simple SUM function in Linq, but also manipulate one of the feilds coming back by doing a Substring on it, here is the original SQL query:
[Code]....
I am having a meltdown over something that seems so simple and yet isn't working. Here's my scenario.
I have an object structure of tEvents, which contains properties of an event like a run of concerts. tEvents in turn contains an entity set of tEventOptions, which include properties like EventDate, Cancelled etc. I would like to query a list of tEvents using properties of the tEventOptions, for example filtering by date.
My pageis using a calendar object to show event dates. So I am trying to find if any tEvents in the List coming back from the database match the date of the day element being rendered in my Calendar control like so (in this snip 'data' is List and results from a db query):
[code]....
Except r, my query result var, is always true no matter what data it receives. I have tried the sub query using other properties of tEventOption and get the same 'true' result each time. I know that the data does not reflect this result so I clearly have a problem with the structure of my query, but for the life of me I cannot find a way to resolve it.
I have this query for getting data through Entity Framework, which works today. Thing is, i want to create the query dynamically, i.e build it up in blocks, but i can't figure out how exactly to do it. I believe if i can somehow save one of the values that i retrieve in the beginning i can do it, but now i retrieve it twice (probably a bit slow as well? Unless the compiler fixes it before quering). Makes sense? Here is the LINQ:
[code]....
I.e based on if various variables have values.
Best way to show the SQL trace of a LINQ query to Entity Framework 3.5? I am using ASP.net and EF 3.5.
Dim dbo As Web.Portal.RBMEntities = New Web.Portal.RBMEntities
Dim Query = From RoleAllocations In dbo.RoleAllocations Where RoleAllocations.user_id = _ID And RoleAllocations.expire_date > Today Select RoleAllocations
Console write the SQL trace?
I am new to this, and I am trying to implement a linq query similar to db.Genres.Include("Albums") command from
mvc music store using my current DB setup. I realize that the tutorial mentions Checlking the "Include foreign key columns in the method" when creating the tables in ADO.NET, but if I am using LINQ to SQL classes, then how can I obtain the same effect. And how do I use
db.Genres.Include("Albums") to simplify my life?
if LINQ to Entity queries the EDMX class or its .CSDL or SSDL XML on its way to getting data from the RDBMS?
View 8 RepliesI'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've got a query such as
Dim MediaQuery =
From m
In dB.DOWNLOADS _Where m.ID = id _Select
which returns a record from the database. One of the fields in the record is a FK to another table. I need to read this value to be able to set a dropdown based on the ID but I can't work out how to access it. For a standard record I can just do the following txtTitle.Text = MediaQuery.FirstOrDefault().TITLE
However with the foreign key it doesn't work like that. I've tried drpGroup.SelectedIndex = MediaQuery.FirstOrDefault().DOWNLOAD_GROUPS.ID where DOWNLOAD_GROUPS is the FK field but it returns Object reference not set to an instance of an object. If you're simply wanting to read some values from a single db record in the entitiy framework and one is a foreign key how should I go about getting the value?
We would like to perform something like this
string strCondition = "FirstName=='abc'"
from p in People.Where(strCondition) select p
In our architecture we are usign both Linq-Sql as well Linq-Entity. So please give some thoughts wehter it is possible or not and is there any way to perform this?
I want to rewrite my urls that contain page name with extenstion and query string value as [URL] .....
is should be rewriter like this: [URL] .....
I have rewrite using Web.config but it is manually entry.
I'm trying to implement URL Rewriting into my existing application and have managed to get the page and links working except that my destination page does not get the query string values.Mycde is based on the example below: http://dotnetguts.blogspot.com/2008/07/url-rewriting-with-urlrewriternet.htmlBasically I have a default.aspx page with links to another page; directory_item.aspx?Item_Id=1&Category_Id=1 directory_item.aspx?Item_Id=2&Category_Id=1 and so on... The code in my web config is as follows;
[Code]...
I have the following url which i want to write a helicon RewriteRule rule
it should check the pattern startat=/mypage.asp and then only executeOriginal urlhttp://www.test.com/welcome.asp?tartat=/mypage.asp&value1=23&value2=3434&value3=1&value4=someothervaluethe new url http://www.test.com/mynewpage.hcx?startat=/mypage.asp&value1=23&value2=3434&value3=1&value4=someothervalue
I have the code below could to rewrite from LINq to SQL to Linq to Entity.
[code].....
I want to use "if statement" in Linq query. How can I do this situation?
For example:
if txtAge.Text=="", I will not use that in Linq Query.
else txtAge.Text!="", I will use that in Linq Query.
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
[code]...
select Groupid,GroupName,onorusername from palgroup where groupid in (select distinct Groupid
View 5 RepliesI 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?
I 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.
Whats the best method to use with MVC? Entity Framework or LINQ to SQL?
View 4 RepliesIm working on a greenfield project and have to make a decision on the technology we'll use for the data access layer. Ive used LINQ to SQL for a few years and am happy and comfortable with this, but now with entity framework available this is another method to consider. Are there any pitfalls using entity framework as opposed to LINQ to SQL ? Ive read that there are performance issues with entity framework, is this true? Id really like to get an overall feel for using one method over the other, anyone have any thoughts/comments/recomendations?
View 1 RepliesI'm trying to learn MVC. Now I wonder whats the different between entity framework and LINQ TO SQL? Wich is the best to use and why?
View 19 RepliesIm new to development for the windows server platform. Can someone tell me the difference between Linq to SQL and EF4?
View 2 RepliesType 'System.Data.Linq.ChangeTracker+StandardChangeTracker' in Assembly 'System.Data.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable
have read all threads but still cant solve the error. I can do insert update and delete but dont know where exactly the error occurs and how??