ADO.NET :: Reading Column Data From Var (using LINQ)?
Feb 2, 2011
I am using Linq to read data from the database, the database has 5 coloumns.Here is the code that I am using to read from the database.
[Code]....
Now, I call this method as : var retrieved_Data = objDataMgrClass.ReadData();Now comes the problem that I am facing how to read each coloumn from this var retrived_Data??? I have tried using foreach loop but i keep getting an error : foreach statement cannot operate on variables of type 'object' because 'object' does not contain a public definition for 'GetEnumerator'.The foreach loop i have used as:
In my application i want to compare data of two users from database table using linq.
lets say i have ten columns in UserMaster table.
Now based on the comparision i want to display result.
Like is 10 out of 10 columns matches for those two users result will be 100,if 9 columns matches then result will be 90 and if 0 matches thn result will be 0.
I would like to select some data from multiple tables and calculate a new column IN the query.In SQL it would look like: (select A, B, ((C * D) + (C * E)) as 'calc' from tab1 join tab2 on.join tab3 on.join tab4 on ...);I've tried this in linq, but it didn't work as I believe.
SELECT IDNum, Max(Convert(varchar(20), (TimeOut - TimeIn), 108)) FROM IO_Times Group by IDNum order by Max(Convert(varchar(20), (TimeOut - TimeIn), 108)) desc";
Into LINQ in C#. The above returns a list of the maximum value of (TimeOut-TimeIn) that corresponds to each unique IDNum (There are multiple TimeOut-TimeIn values for every IDNum).Here is what I am trying now:
from IO_Time in db.IO_Times orderby SqlMethods.DateDiffMinute(IO_Time.TimeIn, IO_Time.TimeOut) descending group IO_Time by IO_Time.IDNum into list select new { ID = list.Key, Time = list });
This returns the correct IDs in the correct order, but the "list" contains everything in the database entry (which makes sense). I have also tried group by IDNum and Time, but then I get unique time entries and multiple IDs returned.I could do a foreach loop and manually sort it all out, but I would really rather not do that.
I know this is probably a pretty easy thing to do and it is if I can upload the file and store it onto the hard drive of the server. What I need to do is read the text file into memory and then parse through it one line at a time. Anyone have any code that demonstrates that?
All I am trying to do is query the database, then get the returned values, so that I can do some calculations. But, I don't understand how to get the values from the database row that is returned, so that I can assign it for usage.
I would like to do something where the logic goes: for the index of [1] (which is just column 1), multiply it by 2. For the index of [2] (which is just column 2), multiply it by 3.
I'm using Linq to Sql to call some stored procedures for more complex work; is there any way Linq to Sql can tell me when the output columns from the stored procedure do not match the properties of my entity object? It seems that Linq to Sql tries its best to match the columns and ignores any mismatches.
I have a column called regdate datetime default getdate() , the column is notnull.I am using linq to sql.I have created instance of that table and when i try to insert record into the table, I am getting daterange exception.(range should be 1/1/1753 to 31/12/9999).In that object I am not setting any value to regdate property as that would be taken care by sql server.If i set regdate = datetime.now.date then record is inserted successfully.I dont want to set any value from front-ent.I want sql server to do that for me like we do it using stored procedure.
I have a Timestamp column in my Table. I want to read the date time value and display in UI.
In Linq the Timestamp column is represented as System.Data.Linq.Binary.
I dont know how to retirve date time value in "MM-dd-YYYY" format from this Linq.Binary
- Why I am using Timestamp?.
I want to perform some operations based on the last modified date time of the particular row. Since I am using TimeStamp column in my Table as version column, It will contain the last modified date details, So i want to read the date time value from this time stamp column to do some other operations.
I have a complicated join between a few tables but I have managed to replicate the error using linqpad and the small tables below. There are references between the COLNAME column and the YAXIS column and also between COLNAME and XAXIS that is not explicitly defined.
The error is "Specified cast is not valid", which originally I wasted time thinking the problem was converting the data returned to my object in VS 2010, but the error also happens in linqpad with no defined object. It seems insane that a bit column would cause this problem. If I change the column type to a VARCHAR it works fine. If I run the generated SQL from linqpad or sql profiler that also returns fine.
want to know if linq to sql auto updated the id column of a class (table row object) after SubmitChanges is called inserting a new row to that table, that would be fantastic, would anyone be able to confirm this?
I am in a serious trouble right now, i wanted to know that how to write a query in LINQ to SQL to retrieve identity column's current value before inserting any value.
I need this cos i m building a windows app n i need to display this value before inserting a record. I have tried DataContext.ExecuteCommand('DBCC CHECKIDENT (Tablename)') but it returns the number of rows modified.
I have the value of Tags for the current document and have run a query to select all other documents that have either of the Tags in there row. for example lets say the current document Tags are (Tag1, Tag2, Tag3)
so from the example rows above all the rows above are returned apart from row[4] Here is the bit i'm lost with, i now want to sort the datatable by how many tags are matched with the current document. so for the example i've talked about so far they should be ordered
i'm writing an asp.net C# web application; i have an in-memory datatable named 'table1' having three columns 'country', 'productId' and 'productQuantity'; i want to pivot that table in order to obtain a new table (suppose 'table2') having the first column 'country' as a fixed column and a dynamic number and names of columns 'product_1', 'product_2', ..., 'product_n' according to the total number of products existing in 'table1'; the first column 'country' must contain the country name; the dynamic generated columns 'product_1', 'product_2', ..., 'product_n' must contain the productQuantity that has been selled for each specific product in the specified country
i'm using Linq query expressions to write the code; the problem is that i cannot hard-code the names neither the values of the products; i cannot predict how much products exist in the datatable;
for now, i'm testing the results using the following expression :
[Code].....
i'm giving an example on how 'table1' looks like and how 'table2' must look like :
view example image of the two tables table1 and table2
I have a database table column consisting of text URLs [URL] In my LINQ-to-SQL-driven gridview, I want to make this a clickable link programmatically, with differing link text (e.g. "Link text"). I'm getting close but am missing some key concept. Here's the core of the .vb codebehind:
Dim dctx As New ResourceMod.ResourceModDALDataContext Dim eleResObj = From eleRes In dctx.Resources Where eleRes.Type = "url" Select siteurl = eleRes.Website GridView1.DataSource = eleResObj GridView1.DataBind()
This displays the raw URL in the gridview (i.e. non-clickable). I've experimented with adding an explicit hyperlink column a la [URL](setting AutoGenerateColumns false etc.), but haven't yet figured out how to assign the asp:hyperlink Text and NavigateUrl fields with the anonymous-type object eleResObj. Using a field construct such as Text='<%# Eval("siteurl") %>' isn't working, presumably a scope issue. Is a LinqDataSource needed in this case, and if so, how would that affect the original LINQ query?
I am looking to sort a column on my gridview by simply clicking on the column rather than clicking on the column header. In the design I have been given, the column header will not be shown, and I need to be able to give the user to sort this column, by simply just clicking any where on the column.
