Databinding Multiple Tables Linq Query To Gridview?
Jun 3, 2010
how can I display a linq query in a gridview that has data from multiple tables AND allow the user to edit some of the fields or delete the data from a single table?
I'd like to do this with either a linqdatasource or a linq query. I'm aware I can set the e.Result to the query on the selecting event. I've also been able to build a custom databound control for displaying the linq relations (parent.child).
However, I'm not sure how I can make this work with delete? I'm thinking I may need to handle the delete event with custom code.
A follow up question concerning the DAL layer part .. The first question about dealing with large objectsI have one table (PlacesTable) that is connected by like 6 other tables (1:Many and Many:Many relations)
In my DAL should I put a big query that join the 6 tables + the m:m reference tables (btw it produces multiple data that I don't need Please refer to my old question) and place all the data in it's specific object property or, should I use a single query for each table and create an object for each fetched table .. and finally send those to the UI ?If I wasn't clear enough please let me know what I further information do you need to know!
As the title sugests, I am missing a (basic?) concept as I teach myself asp.net, linq, and C#. It has been awhile since I've done anything object oriented, so I don't know how much that is impacting this gap in my understanding. Anyhow, here is what I am trying to do. I have three SQL Server tables: PERSON, POSITION, AREA. There is a 1 to many relationship between PERSON and POSITION, and a 1 to 1 relationship between POSITION and AREA. Given the following code I verify who the person is who has logged into the browser:
[Code]....
I want to be able to return all of the AREAs the person is able to access, based on the position they currently hold. I am able to easily do this in a SQL Server query, and I am sure I can do this with a SQL stored procedure once I pass the EMPLOYEE_ID to the procedure. However, I would rather do this in the page_load event, and load the returned results into gridview1 for the viewer. The issue I am running into is in building the LINQ query. When I try to build it, I can only get access to two of the three tables, depending on which table I select with db. Is it possible to access all three tables in the same query?
I am a little new to this concept so bear with me.1) I need to query atleast 35 tables using linq to sql(SQL server database) . I am not able to add all the database entities in Linq to sql classes?
2)(View Model issue) When I use List<Reportcollection> and also List<Receipt> to convert the result then its giving an error that "Cannot convert list<anonymous> to list<string>"
I have a partitioned db where several tables have the exact same structure. I'm able to query the tables using linq, but only by quering the individual tables 1 at a time and by using the explicit table name. For example at the moment, I have 8 tables so I have something similar to the following:
[Code]....
Is there any way, that based on a certain value (stringValue), I could determine which table to query and then code the linq query just once?
I have a couple tables that are kind of unrelated - id like to search through both of them and create a type that i can sift through later
something like this doesnt work
[Code]....
I basically want to create a list of "AnimalSearchResults" that contains all dogs and all cats that have that name Whats the best way to do something like this?
have a database and I've created a DBML Linq-to-SQL file to represent this database. I've created a new aspx page and dropped a linqdatasource and a formview control onto it. When I configure the linqdatasource it gives me the choice only to select * from one table...but I want to pull from multiple tables. e.g. I have tables like simple_person, simple_address, simple_phone, and I want to pull from all of them.
Does anyone have some really great tutorials on how to use link with datasets that contain multiple tables that utilise primary key and foreign key relations? For eample
Table1 - id (PK) - language Table2 -id (PK) -programmingword Table3 -id (PK) -languages_ID (FK) -pgrammingword_ID (FK) -translatedword
Linq search for: Table3.translatedword where Table1.Language ='french' and Table2.programmingword = "yes" does this make sense? im looking for exampes/ tutorials for how to do this? or can anyone recommend any good books on linq?
I'm a newbie to this so bear with me. From what I've read online LINQ to Entity should see the relationships without having to specify the joins between multiple tables. I have a relationship that goes across 4 tables Employee, EmployeeDepartmentLink, EmployeeProjectLink, and Project. The idea is an employee can be in multiple departments and work on multiple projects with it being specified which department the employee is in for that project.
This is a C# MVC3 program connecting to a SQL database using VS 2010 Express.
I have no problem with running this query to find employees on a project:
[Code]....
Tring to do the reverse, finding projects that an employee worked on results in an error:
[Code]....
Error message: The specified type member 'EmployeeDepartmentLinks' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported. So I have 2 questions,
1) Why would it work in one direction and not the other? I've played around with it for a couple days with the same results.
2) Does it matter that my primary key and foreign keys are not named the same since all the relationships are connected in SQL? Ex: in Employee (EmployeePK)--(EmployeeFK) in EmployeeDepartmentLink Trying different stuff in LINQPad I was able to get the 2nd query to work if I specified all the joins which I thought was not neccesary with LINQ to Entity. I converted an SQL query that I made on the server into a LINQ query below which works.
Is it possible to create a table class that can be used for multiple tables? For example, if I have some class:
[Code]....
In LINQ to SQL, this maps to a table with a name based on the class name, DBClass. However, suppose I want to use that class for multiple tables, and it could be an arbitrary number of tables. Is this possible
I have a view that has to render information from 3-4 tables. I therefore chose to create a viewModel for this. I am using EF as DAL.The information to be displayed is SiteId, SiteName, SiteDetails from one table.Associated to Site, other table Event_type has information about Events in the system with fileds like EventId, EventName, Event ScopeId.EventScope is another table with ScopeID and ScopeDesc Also, there is Site_Event_Implemnetation table that stores all the events associated to a site. It has SiteId, EventId, EventUnitIdEventUnit is another table that stores all the unit types.Now my Details ViewModel has to display the info SiteName, SiteDetails. And associated to that a grid of events with info on EventName, Scope Desc, Unit Desc1. How do I formulate my query to retrieve this info in my repository layer using Linq to EF?
I have two tables with a foreign key constraint how can I delete rows from both of them in one transaction? linq to SQL seems to call my deletes in the wrong order. Is there somewhere I can check and make sure the constraint is recognized properly by linq to SQL??
I'm looking for ideas on deleting data from the multiple SQL tables with LINQ (C#).
My existing solution does the following:
1. DeleteAllOnSubmit( Subset of the data from the child table)
2. DeleteAllOnSubmit( Subset of the data from another child table)
3. DeleteAllOnSubmit( Data from the parent table)
4. CommitChanges()
All this resides within a single method, which makes it ugly and not re-usable.
I have considered the following alternatives, but I decided not to use them:
1. Cascade delete on the tables.
2. Do a join on all tables from which I will remove the data, but I'm not sure yet whether I could pass a join query to DeleteAllOnSubmit().
3. Write stored procedure(s) to delete data from each table. I don't have the time to implement this due to a large number of tables and the time constraints.
Is there a way to select data from multiple tables other than the UNION ALL statement. Addtionally I need to select data from a different database.
My current statement is as follows (there are alot more fields but I have shortened it ):
SELECT server.dbo.SRFILE.SR_GROUP, server.dbo.SRFILE.SROWNERSHIP, server.dbo.SRFILE.SRCONMAE, BSFLBWF_1.Incidentx, BSFLBWF_1.Severityx FROM server.dbo.SRFILE INNER JOIN BSFLBWF AS BSFLBWF_1 ON BSFLBWF_1.Incidentx = server.dbo.SRFILE.SRONUMBER WHERE (BSFLBWF_1.Closex IS NULL).........
I'm having trouble doing a left outer join with multiple generic lists tables. I've been researching for hours and there isn't a whole lot out there on this subject and VB (at least what I found).
I have the following Linq query:
Dim DataForGridview = (From s In S1 _ Join c In C1 On c.ID Equals s.ID _ Join v In V1 On v.ID Equals s.ID _ Select New With { _ .dataFieldID = s.ID, _ .dataField1 = s.dataField1, _ .dataField2 = c.dataField2, _ .dataField3 = c.dataField3, _ .dataField4 = c.dataField4, _ .dataField5 = v.dataField5 _ }).ToList()
S1 has a count of 30. V1 has a count of 20. C1 has a count of 10. This query joins the three but ends up with a count of only 10 based on the datakey ID and, of course, only shows those 10 in the gridview.
I would like to show all 30 from S1 in the gridview with blank fields wherever V1 and C1 do not have data. From what I've read I need to do a left outer join. However, all examples I've found are with two datasets.
I've tried multiple times expanding on what I've found by changing it to a group join and also adding the .DefaultIfEmpty() property in the query, but nothing is working.
How can I change the above query to a left outer join with these multiple tables?
One of my peer wrote a query based on multiple tables using joins. One of the table is in a different database The query was taking much time
1. Create an SP 2. Create a temp table and copy all records from the external db 3. Avoid using Left Join as much as possible and use Inner Join 4. Create and use indexes 5. Remove tables/columns that are not necessary
In this scenario, I would like to suggest to use Covering Index, but how can it be created for multiple tables and a temp table?
We have two related tables (inventory, inventoryLocalization) and a t-sql query works on them as follows..
select inv.[code], coalesce(inL.name, inL2.name) as [name], coalesce(inL.description, inL2.description) as [description] from dbo.[inventory] inv left join dbo.[inventoryLocalization] inL on inv.code = inL.code and inL.language = 'de' left join dbo.[inventoryLocalization] inL2 on inv.code = inL2.code and inL2.language = 'en' where inv.[code] like '15.' + '%' order by inv.[code];
to performance improvement, we will try to use these tables from cache not from RDBMS directly. for an asp.net 4.0 project, by c#. We've took both tables to chache with a DataSet and we can reach both of them through that DataSet.
DataSet ds = UtilityCache.getCachedDataSet();
"ds.Tables[0]" is inventory Table and "ds.Tables[1]" is inventoryLocalization Table
But how can we convert above T-Sql syntax to linq2Sql. is it possible to use coalesce for select statement and to join on two tables with multiple conditions ?
I have a quick Linq to SQL question. I am trying to write a Linq query that has multiple where clauses depening on user input. What I would intuitively code is:
Dim arrTerms As Array = txtUserInput.Text.Split(" ") Dim q = From newsitem In db.MyNewsTable _ Where newsitem.Contains(arrTerms) _ Select newsitem Listview1.DataSource = q Listview1.Databind()
Unfortunately, though, the "Contains" operattor does not accept an arraylist, or array, or anything but String.
