I have two tables, Table A and Table B
Table A contains diag_code
Table B Contains diag_code
Table B Contains diag_desc
These codes are used for Diagnostic codes and Non Diagnostic codes.
If table A diag_code = table B diag_code, table B diag_desc is valid and has a value.(Diagnostic)
If Table A diag_code <> Table B diag_code, Table B diag_desc has no value, but it is not null!!!! (Non Diagnostic)
If I do an inner join between A and B on diag_code, then I get the correct values for Diagnostic codes.
.
My problem comes when I try to get just the Non Diagnostic values to show. They show as a null value in a chart, but not from the script.
If I do an outer join, they all show, but I cannot seem to be able to get just the ones where the diag_desc is null/no value relating to the diag_code
| diag_code | diag_desc |
| |
| H221 | Diagnostic fibreoptic endoscopic examination of colon and biopsy of lesion of colon |
| W371 | - |
H221 is Diagnostic and W371 is Non Diagnostic.
How do I get just the non to show, or how do I get a selection box to show Diagnostic and Non Diagnostic as I cannot get diag_desc to show as a null?
Thanks
