Gridview null values for datetime in database results Object Can Not be cast from DBNULL to other types error

Question

I am using the gridview control which is connected to my database with an sqldatasource. I can do updates and deletes directly from this gridview.

When I edit a date field and remove the content, instead of writing null to database, it changes the value in database to 1900-01-01, and if I write manually null to the database, and use the edit button of gridview on that row for some other cell, below is the error.

Object cannot be cast from DBNull to other types.

avani gadhai avani gadhai · Accepted Answer · 2013-02-21T09:46:20

First Check Is the Database column null-able?

You haven't mentioned which version of asp.net framework you are using.

For .net framework >= 3.5, you can use the nullable datatypes i.e. the binding should be with a datetime? field instead of datetime. The error you have mentioned is due the fact that you are trying to bind a null value to a variable of the type, datetime. Use dateime? and your error "Object cannot be cast from DBNull to other types" will be resolved. Or you can do the following in the itemdatabound event:

yourTextBox.value = string.empty
if(((DataRow)e.Item.DataItem)["YourDateField"] != dbnull.value)
{
   yourTextBox.value = ((DataRowView)e.Item.DataItem)["YourDateField"] .toString();
}

You haven't mentioned what you are doing for databinding/datasaving. In the data-saving code do the following:

datetime? saveDate = null;
if(!string.isnullorempty( yourTextBox.value))
    {
     saveDate = converto.datetime(  yourTextBox.value);


     }

//Use the saveDate for the saving.

Gridview null values for datetime in database results Object Can Not be cast from DBNULL to other types error

1 Answers