DataSource Controls :: LINQ To Entity Query - Getting Data From The RDBMS
Jan 1, 2010if LINQ to Entity queries the EDMX class or its .CSDL or SSDL XML on its way to getting data from the RDBMS?
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DataSource Controls :: SQL Query Re-Write In Linq To Entity?
Jan 26, 2010Need 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]....
Forms Data Controls :: Entity Datasource And Query Extender Using LISTVIEW
Mar 9, 2011I have a user control, named productslist.ascx. On pruductslist.ascx, I am using Entity Datasource and a QUERY EXTENDER and LISTview. I have a page Defualt.aspx. On Defualt.aspx, I have a TEXTBOX with a SUBMIT button for searching the site. Everthing works fine so far, AS LONG as the results of the Search is posted back to Default.aspx. What I want is for the results of the search to be posted on a different page.
So I created a new page, Results.aspx and set the postback url to it.
What I want is that when a user clicks the Submit button, after entering a search string, the text the entered is used to execute the query on Productslist.ascx and the results displayed on RESULTS.ASPX. Again, everything works fine as long as the results are posted on same page hosting the usercontrol, BUT I want the postback url to be a different page. I am coding in VB and VS 2010.
DataSource Controls :: Accessing FK From A Query Via Entity Query
Jan 21, 2010I'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?
DataSource Controls :: SQL 92 Compatible Equivulents Does It Mean It Will Work With Other RDBMS?
Apr 4, 2010For example, many programmers prefer CAST over CONVERT because CAST is compliant with the ANSI SQL-99 standard. Does this mean if I used sql 92 compatible functions, it will work with other RDBMS such as MYSQL?
View 1 RepliesDataSource Controls :: How To Do In Linq To Entity
Feb 2, 2010select * from MyTable select "MonthName"= case when datepart(month,date1) =1 then 'January' when datepart(month,date1) =2 then 'February' end , count(*) as CountByMonth from venkat group by datepart(month,date1)
View 1 RepliesDataSource Controls :: LINQ To Entity Getting The First Row?
Jan 14, 2010I am using the following LINQ to entity to get data from my db.
It should return only one row. So i want to be able to get the first row in the set and not have to go through a foreach.
I would also like to check and make sure it is only returning one row, if it returns multiple i need to throw an exception
[Code]....
DataSource Controls :: How To Convert Sql Query Into Linq Query
Mar 10, 2010select Groupid,GroupName,onorusername from palgroup where groupid in (select distinct Groupid
View 5 RepliesForms Data Controls :: Sql To Linq Query / Looking To Translate An SQL Query Into Linq?
May 28, 2010I'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.
C# - Rewrite SQL Query Using Linq To Entity
Jul 12, 2010Hi 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
DataSource Controls :: Entity Query To Validate Ntry Not Already In A Table
Jun 16, 2010I have a button click event that adds a record to a table based on the userid and threadid the user is viewing. I am a bit new to entity so I am stumbling around. I have to where conditions
ThreadID == threadid
UserId == userIdPosts
I have this query but do not know how to execute it and if I have it as is I get this in the yellow screen of death Both the theadid and userIdPosts have data in them.
var query = context.TrackLists.First(t => t.ThreadID == threadid);
context.TrackLists.First(t => t.UserId == userIdPosts);
Sequence contains no elements
Line 90: // find is user has already tracked this thread.
Line 91: var query = context.TrackLists.First(t => t.ThreadID == threadid);
Line 92: context.TrackLists.First(t => t.UserId == userIdPosts);
ADO.NET :: LINQ Entity Framework Query - Construct "nested" Query?
Jan 22, 2011I 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.
Execute LINQ Query Using Properties Of Child Entity Set
Nov 25, 2010I 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.
Simplify LINQ-To-Entity Query, And Make It Dynamic
Dec 4, 2010I 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.
Show SQL Trace Of LINQ Query To Entity Framework 3.5
Oct 13, 2010Best 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?
DataSource Controls :: Linq Update Via .attach() Giving Entity Exists Error?
Jan 5, 2010I have a "simple" method that takes a Linq entity containing the information I want to update. The method then creates a list of counties the information is to be updated for, and tries to update the information for each county.
So user goes in fills form out selects update All counties, and the information in the form should be updated for all the counties for the member. Here is the code.
[Code]....
The first pass through the foreach runs perfectly, the second time through I get an error: Cannot attach an entity that already exists.
What is best way to work around this?
I have though about putting the foreach loop in my business_logic layer, and have it pass both the newRecord and OldRecord, but figured I would ask, before making the code change.
ADO.NET :: Setup Query Result Shaping For LinQ To SQL Instead Of Entity Framework?
Sep 9, 2010I 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?
DataSource Controls :: Query Using Linq To Sql?
Jun 25, 2010I´m using Linq to Sql in my asp.net application, but the problem is:I have a query like this:
[Code]....
My query is not returning anything, how do I do to get this?my problem is with this interval I need to have.
DataSource Controls :: One Linq Query With Two Db Connection?
May 31, 2010I want to use from two db connection in one linq query
My sample is:
int a=1;
if(a==1)
DataClasses1DataContext1 db = new DataClasses1DataContext1();
else
DataClasses1DataContext2 db = new DataClasses1DataContext2();
var q =
from c
in db.F_Groups
select c;
In this code a=1 so db connection is DataClasses1DataContext1
I want if a=2 then db connection = DataClasses1DataContext2
but this code is error.
db connections is completely same but in two deferent class a db connection is sql and another is oracle
DataSource Controls :: How To Convert Sql Query To LINQ
Feb 13, 2010How can I convert this sql query to LINQ ?
[code]...
DataSource Controls :: Linq To Sql Query / Zip Codes?
Feb 18, 2010Im doing thing profile, zip code thing on my site. One table has a list of zipcodes and in the other is a profile and there they keep what zip code they entered. I already have the radius code but idk how to get a list of all the profiles in a radius.I'm going to store the zip codes that come back from the zip code table in a arraylist and put it in a session state so i don't have to keep getting the same thing over and over again. The problem is i don't know how to write the linq to sql query to take the arraylist of zip codes and look up all the users that have that as there set zip code in there profile.
View 1 RepliesDataSource Controls :: Return First Value From A Linq Query?
Mar 12, 2010Is there a way opf getting the first value from a linq query so for example
[Code]....
DataSource Controls :: Add A New Item To A LINQ Query?
May 13, 2010So I'm trying to add a single item to a query I wrote. The query is then pass to the e.Result of a LinqDataSource_Selecting event. This datasource is being used by a dropdown list and label in a listview.
I am trying to add a "New" field to the end of the list.
Currently I have this working, but it seems like a really messy solution. First I make a class with the fields I need:
[Code]....
Then I build the query:
[Code]....
Then a second list and query with the new value:
[Code]....
Finally, I union the two and set the e.Result:
[Code]....
DataSource Controls :: Retrieve Value From LINQ Query?
Mar 20, 2010I need to know how to extract the result of the attempted LINQ query below and set it equal to the strFile variable.Everything Intellisensed OK here but ine 5 shows a syntax error at the parenthesis.
[Code]....
DataSource Controls :: Linq Query With OrElse?
Apr 7, 2010I'm having a problem with a Linq query where is executing the second half of an OrElse even though the first half evaluates to true.
[Code]....
When Manufacturer is null, I get a NullReferenceException. The "Manufacturer.Trim()" should never be executed, because the first half of the OrElse evaluates to true. Just to test it out, I also tried this:
[Code]....
This actually works fine... Manufacturer.Trim() is never executed, and I get no error. Why is the Trim() statement being executed in the first case? If Manufacturer is null, then it shouldn't be.