Databases :: Trying To Figue Out Groupings On Data Tables With LINQ?
Feb 15, 2010
I am having a hell of a time trying to figue out groupings on data tables with LINQ. I am using VB
I have two data tables. I'll define from Table Law = columns (ven_grp,comp_no,acct_unit,description,company)
Table Comps = columns(comp_parent,comp_struct1, comp_struct2, .... through comp_struct9 Now here is the SQL equivalent of what I need in LINQ
[Code]....
For reasons I won't get into I can't use SQL to do what I need to do. this is how far I got with LINQ
[Code]....
which works ok, but I can't for the life of me figure out how to group on the fields I need to and then dump the query results into datatable. I've looked at tons of examples on line and I just don't seem to get it or it does not work the way examples show. Both of my tables are defined as similar "Dim law = ds.tables(0).asenumerable()
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.
I've a problem in MySql.I need to retrieve data from two tables,in which one field is common in both the tables and I need to retrieve distinct data.But all I'm getting is this :
Id Name Initial 1 abc A 1 abc A 1 abc A 2 def B 2 def B 2 def B
I am using mysql as my database.From one of my web pages I want to insert data to 4 tables.All the data should be inserted to these different tables on a single button click from the web page.How can I achieve this?Which is most reliable way to insert data to multiple tables on a single click event?
Will the sql operation with 4 'insert' statements separated by semicolon work for me?
I have two tables: Projects and ProjectsData and I want to execute query with join and get the result in the View. In the Controller I have this code:
ViewBag.projectsData = (from pd in db.ProjectsData join p in db.Projects on pd.ProjectId equals p.ID where pd.UserName == this.HttpContext.User.Identity.Name orderby p.Name, p.ProjectNo select new { ProjectData = pd, Project = p });
What I should use in the View to extract this data. I tried that:
@foreach (var item in ViewBag.projectsData) { @item.pd.UserName }
I want to get data from Projects(which have CourseId) and related CourseName from Courses table.
I have written following code:
var projects = from n in db.Projects join c in db.Courses on n.CourseId equals c.ID orderby n.Name select new { Project = n, Course = c }; return View(projects.ToList());
and I get error:
The model item passed into the dictionary is of type 'System.Collections.Generic.List1[<>f__AnonymousType22[ProjectManager.Models.Project,ProjectManager.Models.Course]]', but this dictionary requires a model item of type 'System.Collections.Generic.IEnumerable`1[ProjectManager.Models.Project]'.
What I need to do in Controller and in View to display this data?
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 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???
The end goal is to be able to reference our address book, and give the user the ability to select a Manager, which then in turn would return all the results for all the users under that manager. This information is stored in our Exchange servers address book. ie when you select on a person's name in Outlook, then Organization, you get their manager, so when you select the Manager on this site, I want it to return the results for all of his/her members.
I have a site that has a dropdown list of users who've entered data into a DB. This list is populated with a User's alias when they enter data.This DB of data (including Users' aliases) contains data from users in multiple groups, and I am trying to figure out how I can access our Outlook exchange.
The problem is I had to create a draftResult class in order to show data that resides in two different tables using linq which means if i want to add or remove a column i will need to do so in the draftresult and in my linq. Here's what my setup looks like: I have two tables (draft, lookUpStatus)
draft table columns idname,status id lookupStatus idtitle public class draftResult { public string draftName {get; set;} public string status {get; set;} }
I want to list the draft name and the status title in a table view. In order to do this, I wrote the following linq in a method in my sqlRepository class and return it to a IQueryable<draftResult>. My controller instanstiates the sqlRepository object and invokes GetDraftListing().
public class sqlRepository { private Table<Draft> _draft; private Table<LookUpStatus> _lookupubStatus; public IQueryable<draftResult> GetDrafLtisting() { return (from draft in _draft join status in _lookuptatus on draft.StatusID equals status.ID select new draftResult { draftName = draft.name, status = status.Title }); } }
The above process works but does not seem as flexible and i'm trying to get a better understanding of MVC and LINQ.
I m having one dataset underwhich i have two DataTables ie Contact & Sales Order.In this two table my ContactId field is primary key in both the tables. I cot some code similar to the following code. But when i copy this code two my .net application it me an error saying semicolun expected ,etc as shown bellow.
Error 37 Invalid expression term 'in'
Because of this i m not able to test the code. can any body tell me how can i achive it . I kust want to inner join this two tables & want to store the result in another data table.
I am having 2 databases namely ach and cart and i am having tables namelt Register and Invoice i would like to add a field in to those 2 tables . Like if i enter a value like some ccyyxxyxyxa this should be saved in the 2 tables...
I have a C# problem I need to synchronize two MS Access tables from two different databases(two databases over a network) which is quite similar, I thought of using two different OleDbConnections and two DataAdapters to fill a Single DataSet and then manipulate the data in the DataSet, I think the source table (database with the primary data) should be loaded first (into the DataSet) then the secondary table from the remote database should subtract the existing records in the DataSet to get the difference then the difference should be Appended to the remote table, but I don't know how to remove the same records from the DataSet and to send the remaining records to the secondary database.
Here is some code I already have, but I don't know how to get this to work:
i need to join two tables in different databases, how it can be done??? and if i want to use sqldatasource control to bind results to some data-bound control how can I configure my sqldatasource control???
I was trying to find out how I can join more than 2 tables using the LINQ-to-SQL syntax. For instance, joining 2 tables in SQL:
SELECT * FROM Table1 AS T1 INNER JOIN Table2 AS T2 ON T1.Key=T2.Column1WHERE T2.Key='17';
can be expressed as:
var Result = from T1 in DbContext.Table1 join T2 in DbContext.Table2 on T1.Key equals T2.ForeignKey where T2.Key=17 select new { T1, T2 };
But how would I join 3 or more tables using LINQ? For example:
SELECT * FROM (Table1 AS T1 INNER JOIN Table2 AS T2 ON T1.Key=T2.Column1) INNER JOIN Table3 AS T3 ON T3.Key=T2.Column2 WHERE T2.Key='37';
I've been searching and experimenting and I cannot seem to find any informraiton on this. One example I found involves putting the result for the frist join into a temp object, and then performing the second join. I'm not sure performance-wise if that's the same as doing a 3-table join directly using a single SQL statement.
I am using VS 2010 I've created LiNQ .dbml file via .. Model>Add New Item>Data>LINQ to SQL Clases I've put table on designer surface using drag & drop. I've done all this from one tutorial. There Is Mapping with arrows between tables in tutorial. How can i do this?
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?
