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 would like to reuse in different ASP.net classes the following code :
[Code]....
However i cannot add this code in App_Code because Session is not recognized in .cs classes.
Therefore i need to create resusable asp.net classes which will contain the previous code.
I came across the article few days ago where somebody said that it's possible to automatically break down ClassName.Designer.CS into multiple classes.
So instead of having Customer and Order class definitions in one .CS file I'm going to have 2 .CS files: Customer.Designer.CS and Order.Designer.CS
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?
Using Linq to Sql how do i group the following 2 tables.
Orders Table:
CustomerID | Name |Date
1 | order1 | 2010-01-01
2 | order2 | 2010-01-01
2 | order3 | 2010-04-01
Calls Table:
CustomerID | Name |Date
1 | call1 | 2010-01-01
3 | call2 | 2010-06-01
2 | call3 | 2010-05-01
I want to group the two tables by date , Result:
Date | Orders | Calls
2010-01-01 | 2 | 1
2010-04-01 | 1 | 0
2010-05-01 | 0 | 1
2010-06-01 | 0 | 1
i know how to group a single table ,from o in Orders group o by o.Date.Date into og select new {Date = og.Key,Orders= og.Count()};
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.
I'm using ASP.NET MVC to create a small web apllication.
Here is my database And here is my class
[Code]....
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.
I am following the Nerd Dinner tutorial as I'm learning ASP.NET MVC, and I am currently on Step 3: Building the Model. One part of this section discusses how to integrate validation and business rule logic with the model classes. All this makes perfect sense. However, in the case of this source code, the author only validates one class: Dinner.
What I am wondering is, say I have multiple classes that need validation (Dinner, Guest, etc). It doesn't seem smart to me to repeatedly write these two methods in the partial class:
[code]....
This doesn't "feel" right, but I wanted to check with SO to get opinions of individuals smarter than me on this. I also tested it out, and it seems that the partial keyword on the OnValidate method is causing problems (understandably so). This doesn't seem possible to fix (but I could very well be wrong).
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??
DataContext.OtherImages.DeleteOnSubmit(myOtherImage);
DataContext.Images.DeleteOnSubmit(myImage);
DataContext.SubmitChanges();
The Foreign key constraint is on OtherImages.
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.
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?
Tables:
WORKORDER and CUSTFIELD
Fields:
WORKORDER = WORKORDERID
CUSTFIELD = WORKORDERID, CUSTFIELDNAME, CUSTFIELDVALUE
There are multiple different type of name/value pairs. I want to specifically return the custfield value where custfield name is "INCIDENT", and the custfield value where custfield name is "NETWORK" all for the appropriate WORKORDERID
I've tried a few different ways and just can't grasp how the linq is supposed to go to get the results I want. I can get an incident value, or network value, but not both.
I have the proper association set up in the dbml so both of these work to get the single value:
var b = from i in edcwdv.WOCUSTFIELDs join p in edcwdv.WORKORDERs on i.WORKORDERID equalsp.WORKORDERID where i.CUSTFIELDNAME.Contains("INCIDENT") select new { i.CUSTFIELDNAME, i.CUSTFIELDVALUE, p.WORKORDERID };
var incident = from wo in edcwdv.WORKORDERs orderby wo.WORKORDERID where wo.WOCUSTFIELDs.CUSTFIELDNAME.Contains("INCIDENT") select new { wo.WORKORDERID, wo.WOCUSTFIELDs.CUSTFIELDVALUE}; So essentially i want to pull the value for each of the fields, INCIDENT and NETWORK
I have a table the uses the same dropdown list in each row. I thought that I could just create one dropdown list and then reuse it in each new row, but the table only ends up with one row unless I create "new" dropdownlist. Am I approaching this all wrong? In the interest of efficiency, is there a way to build the list once and then reuse it by creating another instance of it or something? I was trying to avoid rebuilding that list umpteen times.
private void UserRoles()
{
Table table = MakeTable();
Ewo.sqlDataStore.Administrator sql = new Ewo.sqlDataStore.Administrator();
DataSet dataset =sql.SiteUserRoleList();
DropDownList sel = RoleList(dataset.Tables[0]);
if(tools.validDataSet(dataset))
{
if (dataset.Tables.Count > 1)//existing roles are #2, show the roles the user is part of
{
foreach (DataRow dRow in dataset.Tables[1].Rows)
{
table.Rows.Add(CreateRoleRow(Convert.ToString(dRow["SitePageGroupName"]), sel));//add a row with data
}
}
table.Rows.Add(CreateRoleRow(sel));//add a blank row on the bottom
}
AdminSiteUerRoles.Controls.Add(table);//add it all to the page
}
I have to display records from two tables where foreign key table contains many values for a primary key column how to get the data using linq query???
View 1 RepliesI currently have an ASP .NET MVC / EF4 project that contains many pieces of autonomous functionality such as a blogging, events, contests, wiki, etc.
The entities used by each system are all mapped to my database through one giant EDM file.
This works well for the main site, but I also have a few personal sites where I want to reuse just the blogging functionality from the mains ite.
My biggest problem is that due to the mac daddy EDM file, my blog sites have to constantly have their database schemas updated to reflect changes made to areas of functionality that they don't use (i.e. changes to the events system).
The only other gotcha is that there are some entities (Users and Tags) that have relationships with entities from each area of functionality, making it hard to simply split each area of functionality off into its own EDM.
With all of this said, I'm trying to figure out the most efficient way to set this up.
Should I go down the road of splitting up the EDMs by each area (blogs, events, contests, wiki) and figuring out a way to maintain relationships for the User and Tag entities?
Or should I just perhaps be creating an EDM for each website that only maps the entities that it will actually need? The only problem with this is that my repository layer takes in a UnitOfWork/ObjectContext, and by creating new ObjectContexts for each site I'd have problems reusing my repository code.
how to insert records in multiple table using with foreign key with linq to sql?
View 2 Repliesi am new to this linq concept,
i have used the following code to delete multiple records in my table,
but when i hit the button insteading deleting multiple records only one record is getting deleted
below is the code
protected void Button1_Click(object sender, EventArgs e)
I have an C# ASP application I am writing that needs to have the capability to import a generated excel or a comma delineated sheet each day. A clerk will have this job each morning so it doesn't need to be automated. My problem in trying to understand the solution to this is that the 1 sheet contains loan information, including customer information all in the same sheet. I would like to send certain columns to update information in the loan table and send other information to update the customer table. I need it to create relationships when new loans appear in the spreadsheet.
View 1 RepliesA 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!
For no apparent reason (of course there must be one), my web project will no longer generate LINQ to SQL classes/data contexts!!!I am going about the usual routine of right clicking the project, adding new item, selected LINQ to SQL classes, then dragging over a table from Server Explorer, saving and build but no...the bloody thing won't appear!!!Does anyone know why this might be happening/what have I done wrong?
View 1 RepliesTechnically I have the Data Annoations working with Linq to SQL classes - the problem is when validation
passes. When UpdateModel() tries to do its thing i can an error:The model of type 'MyProject.Models.Employee' could not be updated.What i did was i created a partial class for Employee (that is generated by linq to sql), then stuck a Meta Data class on top of it for the validation
[Code]....
And in my master page i include
<script type="text/javascript" src="/Scripts/jquery.validate.min.js"></script>
I am updating a project I wrote some time ago. At the time my preference was for DataSets and DataSetTableAdapters, but I've now moved on to use Linq to SQL DataClasses. I would like to convert the project to Linq to SQL, but I am tight on time and it's a big job. My question is, is there any reasons I can't develop new modules using Linq to SQL DataClasses along side DataSets and convert the DataSets overtime?
Apart from the obvious confusion it will cause, are there any technical problems I should be aware of i.e. will there be any performance problems using the two methods?