I'm using a c# web service to write an amount a decimal field in a table and it works great except for when the decimal field has been left blank and is therefore null, in which case it generates an error that says something like "unable to update XML document". Unfortunately, the whole point of this web service is to give the user the option to leave that field blank so the web service can do a bunch of calculations and fill it in for them - I could default the field to zero and tell the users that they're allowed to leave it as zero, but I'd rather shoot for the more intuitive solution of letting them leave it blank (for the users, seeing a zero in there could cause problems).
The error occurs at this point in the code:
columnIndexFieldAmount.Item = 30m;
If the field is NULL it throws an error. Are there some adjustments I can make that will allow it to write to a NULL decimal field?