Error returning a DataTable from a WCF service call

Not debating the merits of whether its appropriate or sensible to return a DataTable as a response from a web service, but if you receive an error like I did make sure to check the following:

1. The DataTable needs to be named.

    Before (causes an error):

public DataTable ExecuteDataTable()
{
    return new DataTable();
}

    After (no error):

public DataTable ExecuteDataTable()
{
    return new DataTable(“Test”);
}

 

2. Ensure that the packet sizes configured for WCF are large enough to accommodate a serialized DataTable with the data content you have in it. Serializing a DataTable to XML results in some fairly large XML documents and can easily surpass the packet limits in the default WCF configuration.