Clever Geek Handbook

Sorting ASP.NET GridView in a calculated field

I have a DataBound GridView. However, I have one column where the value comes from the calculation in the code behind - it is displayed inside the TemplateField.

How can I sort my grid based on this calculated value?

0


source to share


4 answers


Put the original returned data in DATASET or DATATABLE. Add a new column to DATATABLE for the calculated field. Pass this data by doing the necessary calculations and placing the result in the specified calculated field.

Create a new view based on the datatable and sort the view by the calculated field. Bind the grid to your data view.

Dim DT as DataTable 
DT = GetDataTableFromDataBaseMethod()
DT.Columns.Add(New DataColumn("CalculatedColumnName"))
For each row as DataRow in DT.Rows
    row("CalculatedColumnName") = PerformCalculations(row)
Next 

Dim view as New DataView 
view.DataTable =dt 
View.Sort = "CalculatedColumnName DESC"

datagrid1.Datasource = view
datagrid1.Databind


Or, if possible, do the calculations in the SQL statement, re:

SELECT Col1, Col2, Col3, Col1+Col2+Col3 AS LineTotal FROM Table;
+7


source


One possible solution would be data padding rather than grid binding. Then use dataview with sort set to your computed column and bind to grid in code.



0


source


Another solution is to add a calculated column to the database table. This allows the computed column to be returned in the same SQL statement that loads the rest of the row, but unfortunately requires a database schema change.

0


source


Note that adding a column to datatable marks all rows as updated, so when saving the database it will try to update all records.

0


source






More articles:


All Articles