I wish to retrieve data from a DataTable using Linq, and I do this by first creating a DataTable with the data and then using Linq to query:
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My problem is, that the column "enddatee" has 'holes', meaning that some rows does not have a value. This means that the convertion to DateTime will fail for some rows. How can I get around that?
i use a datatable to populate my gridview, how do i retrieve database to datatable's column?
View 3 RepliesI have a data table I need to convert to XML. I know I can use datable.WriteXML but I need to rename the elements as the column names coming from the Oracle db are ugly. I found this snippet somewhere:
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It looks like what I want but when I paste it in my code it shows an error on select Cannont convert lambda expression to type 'string' because it is not a delegate type.
I am new to linq and for that matter to C# (done a lot more vb). I am going to read the books but I need to get this done pretty quick for a project.
I would like to implement LINQ IN ASP.NET for filter required data from datatable. I have doubt that what is right place. I have following options
At presentation layer *.aspx.cs
At our Business layer.
At our Data base layer, where query for database happen which is return as a datatable to business layer. Business layer then return the result to presentation layer.right place for LINQ because now i have to further filter data from datatable as per user selecter filters.
i could bind the data form tables to dropdownlist in asp .net using linq.
ex:
var res=from n in dc. contacts where n.location==Hyd select new{n.Id,n.Name};
var res1=from n in dc. Morecontacts where n.location==Hyd select new{n.Id,n.Name};
dropdown1.Datasouce=res;
dropdown1.DataTextField="Name";
dropdown1.DataValueField="Id";
[CODE]...
I have records in database as
hotelid amenitieid
17774 7585
15636 7585
25363 7585
36933 11236
21412 45696
23521 65474
15636 65474
21412 65474
now in above, if i want only those hotelid where amenityid is 7585 and amenityid is 65474 and not any else hotelid , then how to use select query in datatable in asp.net
I have a ListView which I populate using DataTable.
In each row I have a delete button. When the user clicks on the delete, that particular row is deleted in the DataTable Table.
After I perform the delete, I want to avoid page reload just to populate the ListView with the new set of records without showing the deleted row.
I suppose LINQ is the best choice for this. But I am unable to implement it.
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What is wrong with this code?errors: string myname = dt.Rows[i][0]; - Cannot implicitly convert type 'object' to 'string'. An explicit conversion exists (are you missing a cast?)I tried the followingobject myname = dt.rows[i][0]; --if i use object instead of string, i had no errors.How do i retrieve the value from a datatable column into a string in c#?Error2 - if (Name = myname)Cannot implicitly convert type 'string' to 'bool'
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'DataTable' is an ambiguous reference between 'System.Data.DataTable' and 'Microsoft.Office.Interop.Word.DataTable'
View 3 RepliesMany times I need to manipulate with DataTable after I get data from database using adapter.Fill(table).
Usually I calculate data in DataTable by using loops. But I know that there is simpler way using LINQ. I know some basics about that just for strongly typed objects.I can't find how to do this with DataTable that is not strongly typed. How could I get all DataRow or Filtered DataTable (not just value for the field) from table for that conditions:
- where the specified field of the table contans MAX/MIN/AVG value,
- where the specified field of the table equals to some value.
I got the following query to group the table. I am wondering how to add a subtotal record with anonymous type.
string prevOriginator = string.Empty;
var oOriginator = (from I in dtIssue.AsEnumerable()
group I by new {RaisedBy = I.Field<string>("RaisedBy"), ItemType = I.Field<string>("ItemType")} into grp
[code]...
Is there option to convert from Linq.IQueryable to DataTable with some sort of CopyToDataTable() function. I am trying this.
View 2 RepliesI would like to get the distinct value form DataTabel using LINQ.
For example my sample table,
[code]....
1. How to get the distinct Country from Country you like column and the return records as Array or DataTable? (I want only India,USA,UK,Germany )
Is there any way to filter the record values using LINQ?
how to convert a linq query to a datatable
this is my query
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how can i delete a row in datatable using linq to dataset?
I have a dataset in my project, need to delete some rows filtered by ID
how can i do?
Its related to datatable in gridview store in session and then session retrive and store to database. basically i am using gridview here creating new row for button click and these row adding untill user's last entry then submit all these entry to database. so i want to use session variable to store this data temporarily and after final entry user click on submit button and all data shold be save in db.
View 9 RepliesI have a datatable which has been dynamically generated from FoxPro tables using a UNION Select statement. e.g.
SELECT * FROM x UNION SELECT * FROM y UNION SELECT * FROM Z ORDER By v_alue1
This produces a datatable with about 100 rows, each containing many fields, one of which is c_olor. From this datatable, I would like to select the distinct colors and then output in a dropdown.
I have a public class Color which just has one property which I can then use as the DataTextField and DataValueField for the dropdownlist
[code]...
However this never results in the distinct colors.
I have searched and searched for what I am looking for, and this seems to be one of the methods to produce a distinct set of results, but this and the others do not work.
My reasoning behind getting the colors this way, is that I need to get various other distinct values from the same UNION SELECT datasource, so would just do one DB call, cache the results, and then just used this cached datasource to retrieve all my distinct values.
using linqs how to fill datatable using linq to sql in asp.net
i have one storedprocedure to select data from table
and one s.p for insert the data and one for update the data
how i use these s.p to insert and update the data using linq. to sql
I am gettin error in this code
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I'm having a spot of trouble figure out how to write my linq query so that is allows a decimal field in my datatable to be null
Right now I have this:
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But it's not working. The error I am getting is: Cannot cast DBNull.Value to type 'System.Decimal'. Please use a nullable type.so how do I get it to allow program_ar_id to be null?
I call a stored procedure using linq. I want to convert the ISingleResult output to datatable. what can I do?
DataClassesDataContext Dac = new DataClassesDataContext();
var ExitResult = Dac.Retrieverelations(WorkshopCode);
now I'm using below code for converting but I need a better solution.
D
dataTable dt = new DataTable();
dt.Columns.Add("Id", typeof(Int64));[code]....
how to select the mac element value. Here is my code that not working.
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I want to get the customers info and companies of this companies of products they deal with here is my query in linq
var query = from sd in db.Survey_Details
select new
{[code]...
customer table has about 3000 customer who every one of them fill a survey of 2500 product till now survey_details table has about 90,000 recored an will increase by 100% every year this query run good without binding in RowDataBound when i want to work with RowDataBound this is too slow and data never come i think i may take about 5 hours to come
i have a link query that retrun all the records that have their status = 'completed' ordered by their ids, but i want to return only three records not all the records
View 2 RepliesHow can I retrieve the row ID immediately as I insert a new record with LINQ? I need to refer back to it to update the row since it will be the only unique data in this particular table ( it's the primary key and the ID number is auto generated)
View 3 Replieshow to extract DataTable or DataSet from Linq Query or List. e.g I have linq query like this
MyDBpDataContext dcSp = new MyDBpDataContext();
dcSp.myProgrammSP().ToList();
I wrote an Sp which sends a Table as result and I have code which is already using DataTable So I want to convert this result in DataTable.