"DataTable already belongs to another DataSet"

asp.net, c#, dataset, datatable, exception

Solution

It depends on what your function that retrieve the datatable does. If that function use a `DataAdapter` and fills a dataset then you have the `DataSet` property of the table automatically assigned and you need to remove it before assigning a different DataSet

You could try this to remove the original DataSet and use your own

    DataTable generalAlertData = GetTable();
    DataSet u = generalAlertData.DataSet;
    u.Tables.Remove(generalAlertData.TableName);
    AlertSet.Tables.Add(generalAlertData);

So, if your hypothetical `GetTable` works in this way

public DataTable GetTable()
{
    ...
    SqlDataAdapter da = new SqlDataAdapter(cmd);
    DataSet ds = new DataSet();
    da.Fill(ds);
    return ds.Tables[0];
}

then you have the DataSet assigned to the returned datatable. Instead this code doesn't assign anything to the `DataSet` property

public DataTable GetTable()
{
    ...
    SqlDataAdapter da = new SqlDataAdapter(cmd);
    DataTable dt = new DataTable();
    da.Fill(dt);
    return dt;
}

Problem

I can't figure out why I am getting a "DataTable already belongs to another DataSet" exception. Here is my code: ``` DataSet AlertSet = new DataSet(); DataTable generalAlertData = new DataTable("GeneralAlertData"); generalAlertData = //function that returns datatable //throws exception AlertSet.Tables.Add(generalAlertData) ``` When is another dataset being created and when is the generalAlertData datatable being added to it? I tried using a slightly different syntax to create and add the table and got the same error: ``` DataSet AlertSet = new DataSet(); DataTable generalAlertData = //function that returns datatable //throws exception AlertSet .Tables.Add(generalAlertData); ```

Original source