i have two tables tblProduct and tblCategory, what i am trying to do is populate a gridview, i have LinqDataSource binded to the grid and the correct association made inside the .dbml (tblProduct.CategoryID to tblCategory.ID).
To show the fields from tblCategory instead of the tblProduct.CategoryID in the GridView i am using :
This works fine inside the VS2008 debugger, but once its published to the server (2003 + IIS6.0) the column that belong to tblCategory simply don't show, instead of having the category name (tblCategory.Name) displayed like it does inside the debugger it is blank, no errors simply wont show.
I have written a page which uses Linq to query the database and bind the resulting IQueryable to a datagrid. I have a partial class which contains extra properties which derive their values based on other values brought in from the database.
Sorting works fine on fields that are actually in the database but not for the derived fields. When I attempt to sort on such a field I get an error saying "The member 'Trip.Difference' has no supported translation to SQL. how to allow sorting on these derived fields?
For some reason my DataContext is not showing all the normal methods like SubmitChanges() etc in the intellisense.It also won't compile if I type in db.SubmitChanges();Any idea what I'm doing wrong? Normally I don't have this issue, I have several other projects that work fine...
I have a query that returns a field called Type. Possible values for Type are A, B, C, or Unknown. I want to create a table that will show the number of rows of each Type but not the not the Unknown type. Also I like the table to show the percentage of known types versus total types. So the table show look like this:
Type Count
A number of rows with A Type B number of rows with B Type C number of rows with C Type
Total: (number of rows with A, B, or C Types / number of all rows with A, B, C, or Unknown Types)Please someone tell me how to do this in Visual Studio 2005 reports.
i have a template field which shows a picture of a paper clip. Upon click it will open a file from a shared directory. It is a basic application for Expense Reimbursements in which users are allowed to upload scanned expense receipts. After the receipts are uploaded they can also be viewed by clicking on the paperclip icon. hile I want them to be able to save and open the files from the shared directory, I do not want them to know what the directory name is. I want to prevent them from viewing other user's expense receipts. Share name: \serverAExpenseReceipt$
Currently I'm writing an ASP.net webforms app, which works with a table containing 15 fields. I'm using LINQ to SQL which is very good to use and everything, but when i need to bind the fields with the text boxes (15 of em), whats the best way currently I'm doing this
[code]....
Also what should i do to implement the Move next and move previous functionality like a recordset i mean how can i move to the next/previous "student" in db.Students collection.
I am having a hard time attempting to update a single field without having to retrieve the whole record prior to saving.
For example, in my web application I have an in place editor for the Name and Description fields of an object. Once you edit either field, it sends the new field (with the object's ID value) to the web server. What I want is the webserver to take that value and ID and only update the one field. There are only two ways google tells me to do this:
1) When I get the value I want to change, the value and the ID, retrieve the record from the database, update the field in the c# object, and then send it back to the server. I don't like this method because not only does it include a completely unnecessary database read call (which includes two tables due to the way my schema is).
2) Set UpdateCheck for all the fields (but the primary keys) to UpdateCheck.Never. This doesn't work for me (I think) due to my mapping layer between the Linq to Sql and my Entity/ViewModel layer. When I convert my entity into the linq to sql db object it seems to be updating those fields regardless of the UpdateCheck setting. This might be just because of integers, since not setting an int means it is a zero (and no, I can't use int? instead).
I would assume this is possiable but I cannot seem to find it anywhere. I just one the contents of a single field, I don't see why I have to return the how
record to get get that information, here is my current code, how can I make this better without returning the entire record, for just getting contents of one field.
how i call a image field from another table? the image field in the same table is working fine but the one on the other table is not. I have created the foreign key and made the connection... What else do i need to do to call that field? Page Load:
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:
[Code]....
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 have an Entity class which has a Dictionary of fields called Data. Now I want to sort Entities by a field in Data. I was able to verify the Linq expression for using fields in a dictionary as e.Data["UserId"] as this seemed to work perfectly when I used LINQ to Objects. e.g. Entities.OrderBy(e => e.Data["UserId"])
However this same expression does not generate the correct NHibernate criteria and errors out finally with a NullReferenceException for propertyName at Hibernate.Loader.Criteria.CriteriaQueryTranslator.GetEntityName(ICriteria subcriteria, String propertyName)in CriteriaQueryTranslator.cs: line 541.
On debugging through NHibernate code, I figured that NHibernate.Linq.Visitors.MemberNameVisitor.GetMemberName(ICriteria rootCriteria, Expression expr) returns a null string in place of the field name after visiting expr using its visitor. This seems to be the cause of grief. I am using an older version of NHibernate (2.1). Are there any limitations in the NHibernate Linq visitor I should be aware of?
I want to access the data from datatable object. When i trying to get the fieldslist usng "Field" method. But I could not find the method with my table object. Eventhoguh i forcibly write a method and trying to access the fields, It is giving the below error for the first join in query. Rest of the lines are fine.
What is the reason behind it.
The errro: "Error 2 'LINQ2DB.SP_VS_OP' does not contain a definition for 'Field' and the best extension method overload 'System.Data.DataRowExtensions.Field<T>(System.Data.DataRow, string)' has some invalid arguments"
What is the meaningof the error. Shall i do any other changes in the query line?
var QueryChnl = from oSPOP in SPOP.AsEnumerable() join oDiscChannel in DiscChannel.AsEnumerable() on oSPOP.Field<int>("spid") equals oDiscChannel.Field<int>("SPID") join oChannel in Channel.AsEnumerable() on oDiscChannel.Field<int>("channel") equals oChannel.Field<int>("channelID") where oSPOP.Mappingkey == 3200004 select new { oSPOP.Mappingkey, oChannel.channel, oDiscChannel.STATUS };
I have 2 fields in my gridview one called ScriptType the other BagNo, when a user click the edit button, I would like the BagNo filed to be disabled if the ScriptType field is = "TTA" and enabled otherwise. How can I do this?..something along these lines see below..I am using VB..
I have a grid view, and I add new column as a hyper link field, I want the navigationURL for this field to be Pageexample.aspx?ID=other field value like this
I have a table added to a dbml file in my website. The website is already deployed to Live server. Now I have been instructed to a add a new field to the table. The field will be defaulted as getdate().
I don't plan to modify my dbml file for this change since the filed holds a default value. Will it cause any issue(performance related or any other). I am sure that I will not have to use the newly added field in the website. I am new to LINQ.
I have a Listview with a LinqDataSource. I am allocating a resoure called Bladder Scanners to clinicians on the day selected. The field in the database, 'Allocated_Bladder_Scanner_Id', allows nulls. The 'nullable' property of the field in the dbml is set to allow nulls.In the edit template, I have an unbound dropdownlist (drpBladderScannerDropdown) with an 'empty string' item added to cater for nulls, and AppendDataBoundItems="true".In order to show only bladder scanners which have not yet been allocated on the selected day, I am databinding the dropdownlist to a dictionary of unallocated bladder scanners in the ItemDataBound event. I then add the currently selected bladder scanner as a listitem and set it as the selected item. So far, so good, all works well. However, if the clinician has a bladder scanner currently allocated, and then the user elects to not allocate the clinician a bladder scanner on that day by selecting 'Nothing' from the dropdownlist, the LinqDataSource fails to update the field. It does not throw an exception, it just doesn't set the field to nulls. In ItemUpdating I have the following code:
I am trying to update my table ARTICLES and it has a field COUNTER, Everytime a user enter this ARTICLES, the page_load event runs a LINQ to SQL query taking the QueryString as parameter, increasing the COUNTER field in 1.
Say I have a table Comments with these columns: Id, Comment, Category, CreatedDate, CommenterIdI want to get the top 5 categories from the Comments table (based on the count of each category in that table). How can I do this in linq, to return either List or IQueryable?
