Field 'tblXXX.PO#' can't be a zero-length string.

[cppiston]

I have an Access front end with linked SQL tables. when I try to run the action, I get this error: Field 'tbl_XXX_.PO# ' can't be a zero-length string? What should I do? On the table itself where it gets the data from is blank, no value?

 

[moonshadow]

The basic problem is that you're trying to put a '' (i.e. a string with nothing in it), into a field on SQL Server that won't allow it. You can either change the value to a null (assuming the field will take it). In SQL you would do it thus:
NULLIF(fieldvalue,'')
which returns null if the fieldvalue='' or else the fieldvalue.
Otherwise you could try and default it to a single space thus:
isnull(Nullif(fieldvalue,''),' ')
Note the space between the second set of quotes. This basically says: If it's '', set it to null, then if it's null set it to ' '.
Let me know if this don't help.