"Failed to execute deployed method 'ListOptions', column argument cannot be null" error

John Hartley

First of all I am a newcomer to Metastorm, and to the community, so apologies if this is a basic developer error.....

 

Secondly, I'm trying to prepopulate a drop down box in a form with name value pairs. Specifically to show empnames but the value being stored their empid so I can use this to populate other elements on the form. I've created a dataconnection to our Personnel database, created a data business object that uses that dataconnection, also a process business object with variables and now I've set about trying to populate that dropdown field bound to a specific business object variable.

 

When I use the 1 column list of values option everything works fine - when I choose either the empname or the empid from the data business object. When I use the name-value pairs option and choose the same in each one - either empname empname and empid empid - again it works fine. When I choose name value pair - Name and empid as value it comes up with the error above.

 

I noticed that when I populated with the 1 column list the dropdown it had a blank entry at the top so I changed the form - When user loads form event - to prepopulate the drop down with a specific name using assign variable activity. Again this works fine with either in the 1 column list option but not with a different name and different value in the pair. It also strangely works with empid as both name-value but not empname. I haven't as of yet tried the Code Activity activity to do the same.

 

I do notice however, when I did this with the 1 column list the blank entry still appeared only not at the top and I wonder if that's related.

 

I've tried changing the business object variable I''m binding to an integer as well as a text, and tried using a CAST statement in the SQL behind my data connection in case it is a type conflict but again with little joy - although I do not think this is the present issue..

 

I know this is very basic functionality, and I'm sure its possible, as we did something similar on our training course in the summer, but I'm now at a loss at how we did it / what to test next. Should I be using sql to populate the drop down ?

 

I am using Metastorm 9, and any suggestions at all would be welcome. Also apologies for the slightly convoluted first posting to the community.

 

John

John Hartley

Gave up on this error in the end, but did manage to do the same functionality using a textfield and a datagrid instead of a drop down. Attached are the steps I followed.