Forms Data Controls :: MS SQL 2005 And DataSet - Computed Column
Feb 16, 2010
I have a datatable in MS SQL that has FirstName and LastName. In MS SQL I created a computed field called FullName that was ((rtrim([LastName])+', ')+rtrim([FirstName])) I created a DataSet and a Business Logic Layer. In my typed DataSet I saw FullName in the listing when I created it. I am able to use FullName in my webpage. I use it to populate a dropdownlist. However, now when I make changes to the Customer Table I am getting this error message (seen below)
Question: Should I have created the field FullName in my MS SQL Table or should I have left it alone and somehow just added a column to the DataSet and placed an expression in the FullName column? The column "FullName" cannot be modified because it is either a computed column or is the result of a UNION operator. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Data.SqlClient.SqlException: The column "FullName" cannot be modified because it is either a computed column or is the result of a UNION operator. Source Error:
[Code]....
Source File: c:Users ottfarmsAppDataLocalTempTemporary ASP.NET Filesinternalauburnriverside98ea0e1f2a7f0720App_Code.lbdcba1v.2.cs Line: 1240 Stack Trace:
I have stumbled into a problem in which Im having a hard time solving. I have a linq data setup(based on a mssql) where a Purchase Order contains a number Equipments - each equipment has a price. I have a gridview that shows the summed price of the equipments that are included in a Purchase Order. This sum is currently being calculated on RowDataBound through a "listOfEq.Sum(Eq => Eq.PurchaseOrderPrice);" expression which works without any problems. My problem is that I want to be able to sort the gridview based on this summed value, which I cannot do with a normal sortexpression. My next thought was to create a function in my database to calculate the sum instead and then use this is my data basis for the summed column. I have created a function like this:
[Code]....
I want to create a sortable column based on this data. My thought is something like this:
[Code]....
Displaying the correct information is not a problem, however creating the sorting is. Im not sure what to put in the SortExpression. Anybody got an idea of what to do? Perhaps I am forced to use a computed column for this however I dont know to create this column when its based on another table. If this is the case, any idea about how to do create a computed column thats based on data from another table?
I'm trying to define a computed column that will contain an auto-incremented number. In other words, I want it to work exactly like identity, but since I can have only one identity column per table, I wanted to make a computed column that reads its latest value and increment it by 1.
And I want to add a final 'Total' column that calculates (originalCount - NewCount) * unitCost and updates it as the user enters a number in the NewCount text box. Can I do this just with .net, or do I need to use Java? If the latter, how do I tell which Gridview cell to update?
I have a column that contain date (of type datetime), i also want to add another column that will contain 1 Or 0 depends if the value of date has passed the current date or not.
After looking for a driver to open legacy dbf drivers to connect, the next level trouble a have is this one: first, i can retrieve the data but when trying to filter by a parameter (somesc columns) i get an error. The error says about the database can't determine. The error is a columm tha is formated ( 1234 ) about 8 space, fixed. The values in the query appears like that. I resolve this by Trimming Ltrim(ColumnName) and i get this (1234). Now in SqlExpress, how can i filter by the new Trimmed Expression? (This is a primary key that the DBF use)
Using vs2008 I have a SQL Server database attached to my web app. I want to use a computed time column in the database, along the lines of :
timenow is 1 column hoursleft is another column timeend would be another column.
I want timeend to = timenow + hoursleft. Is it possible to do that, and if so what would the formula be that I would enter into the computed column field, and, what datatype would the columns be, timenow and timeend I would expect to be time(7) and hoursleft an int. But is that correct?
I have a table of people with columns holding bits of info about them. I also need a variety of computed columns such as FileAs (lastname + ", " + firstname) and CityStateZip (you get the idea). I am wondering where best to put these definitions. It's worthwhile to note that the user will want to search for things as seen on the page, not the little atoms in the table. For example, searching on ", e" finds everyone whose first name begins with E. Typing ", az" to get everyone who lives in Arizona.
I noticed that linq-to-sql queries only recognize the fields in the table definitions, not any that are added in the partial class associated with the dbml. Linq-to-sql does work against computed columns in the database; however, the column definitions--especially for international address formats--will become very complex and much better handled in code.
The following query returns me the column name from the table in the database, and stores the column name in the grid. How can I change the column name in the grid using following code, if its possible?
DataSet p_dsInformixDataDs = new DataSet(); string cmd = "SELECT * FROM CUSTOMERS"; try { using (IfxDataAdapter da = new IfxDataAdapter(cmd, m_InformixDBConn)) { da.Fill(p_dsInformixDataDs); } } DataView myDataView = new DataView(m_dsInformixDataDs.Tables[0]); if (myDataView .Count > 0) { GridView1.DataSource = m_dsInformixDataDs; GridView1.DataBind(); }
i have designed a database into the vs 2008 mobile database. my batabase has three column column1(int),column2(int),column3(int) and i want to set the value of val(column3)=val(column1)+val(column2); how and where to set the computed column value.
I want to dynamically bind dataset values into datagrid's header datafield.
Is it possible? To be more clear, when you click on datagrid's (Collection) from properties window, you get selected columns created from Bound column. So in those columns I want to dynamically display dataset's table values in those columns.
i.e like ds.Tables[0].Rows[0][0].
Is it possible to do it in Datagrid ItemDataBound function like,
e.Item.Cells[1].Text = ds.Tables[0].Rows[0][0]
or something like this? I know the above code is wrong and wont work since I tried it out and while building it throwed error saying, Cannot implicitly convert type 'object' to 'string'.
i am creating a dataset from SP Sp when executed in query analyser dislays the output but when i used the same for creating datset , its created but i dont get any columns i checked the xsd in notepad but there is no column source names
Codebehind: creating dataset, getting data from sql with adaptor and filling into dataset object, then setting detailsview's datasource. I add 2 button to above template to able to edit data at asp page, and added event handlers:buttons:
[Code]....
My question is, what to do inside the detailsview update event function to able to edit and update data. My method can be wrong too.
I follow the tutorial and create DAL with Dataset. I created a Table Adapter with many column, but when i Call a simple Get for 2 column only. The system display 2 column and the rest column with empty data.
example: Table with 40 column define in Dataset in DAL. I have GetMember from Dataset with 40 column, some request only 1 column (with 39 empty), some request 22 column (with 18 empty column). Will this affact the performance?
I have a stored procedure in my database that sorts a dataset by distance from the specific address input by the user. The distance is created among each individual users query and the sorting of distance occurs within my stored procedure, the distance is not returned in the output. Is there a way I can create a temporary column that returns the distance so that I can give the user an option to sort by distance?
I have a gridview which is binded to a Sqldatasource. I would like to replace a column data field value to 'Not Applicable' if that column has got a value of 2 in database.
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.
