Binary columns in a DataGrid bound to a DataReader

ghell · 10-22-2009, 05:23 PM

I am trying to use a System.Web.UI.WebControls.DataGrid with a SqlDataReader as the data source.

The DataReader may contain a wide variety of data so I do not know which columns I will need in advance.

This all works well apart from for Binary data (such as a varbinary type in SQL Server 2005). It just skips these columns entirely. If I try to use just a binary column in the query, I get the following error:

Quote:

System.Web.HttpException: DataGrid with id 'SqlDataGrid' could not automatically generate any columns from the selected data source.

Is there any way to define how to generate these columns? I always want them to just display as hex, as they would in SQL Management Studio.

SouthwaterDave · 11-06-2009, 06:22 PM

I see you are still using a DataGrid. Are you using an old version of ASP.NET? 1.0 or 1.1, perhaps?

The ObjectDataSource could be the answer to your problem but I think it was only introduced in ASP.NET 2.0.

See http://quickstarts.asp.net/QuickStar...lang=VB+Source for an example of how to use an object data source with a GridView. The select method of the data source class executes SQL and puts the results into a DataTable. You can add code to transform columns or add columns, as required, before returning the results to the web page.

(You can use AutoGenerateColumns="True" for your GridView if the user is allowed to make choices that affect the number or type of columns output to the web page.)

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11-06-2009, 06:22 PM	PM User \| #2
SouthwaterDave Regular Coder Join Date: May 2007 Location: UK Posts: 166 Thanks: 0 Thanked 18 Times in 18 Posts	I see you are still using a DataGrid. Are you using an old version of ASP.NET? 1.0 or 1.1, perhaps? The ObjectDataSource could be the answer to your problem but I think it was only introduced in ASP.NET 2.0. See http://quickstarts.asp.net/QuickStar...lang=VB+Source for an example of how to use an object data source with a GridView. The select method of the data source class executes SQL and puts the results into a DataTable. You can add code to transform columns or add columns, as required, before returning the results to the web page. (You can use AutoGenerateColumns="True" for your GridView if the user is allowed to make choices that affect the number or type of columns output to the web page.)