There      are     no      repeating     arguments in GetValues or SetValues. The syntax checker won't catch it because it doesn't validate each method's arguments.  Where would you have gotten the idea that these functions supported more than one pair of arguments?

You should refer to the online File Layouts and Object Reference.

https://help-sage100.na.sage.com/2020/FLOR/

Although there is a GetValues method that exists in the SY_Service class, it doesn't work the way you think.

https://help-sage100.na.sage.com/2019/FLOR/#Object_Reference/SY/SY_Service.html?Highlight=getvalues

It accepts two arguments. The first is a comma delimited string of columns, the second would be a variable initialized to a blank string. It will return the comma delimited values for each column passed in the first. This works on a single record.

SY_Maint does have a SetValues method which is similar but you pass the comma delimited columns in the first argument and the comma delimited values in the second argument.

https://help-sage100.na.sage.com/2020/FLOR/#Object_Reference/SY/SY_Maint.html?Highlight=setvalues

Go to custom office | user defined field and table maintenance and right click on the so_invoice_detail table and select advanced field settings.  Click on the PLUS, select your quantity ordered field and set the default value to 1.

No scripting required.

Be careful with setting a default value.  You might get errors when entering comment lines and charge lines (where quantity cannot be set to 1).

Hmm.  Never noticed that to be an issue.  Although it is interesting to note that if you put in a comment line it is putting in a quantity of 1.  Normally you would not be able to access that field.

I wonder what that might do to getting a sales order to completed status?

Good point Kevin.  Might be worth testing a little further to make sure there are no surprises.

The most common problems happen to us when we make a CI_Item field required, not thinking about Misc item codes (where the field is not on the data entry screen). 

Advanced field settings are very powerful, so I always try and think through all the details.  Test, test, test.

I could see where making a field required could cause problems.

I've scripted a default quantity and had pop-up errors for charge lines and comments (so I had to add an ItemType filter).  Interesting that Advanced Field Settings bypasses those checks.

I always thought that the Advanced Field Settings would take those things into account. Good to know that this isn't the case. So the best / most controllable option is a script on Table PreWrite that raises an error if the checked condition isn't met.