The special missings section of the v4.0 post was four lines: what they are,
that the adapter supports them, and a video. It is now three sections.
- What special missings are: the 28 missing values, why they exist, and how
they behave as numeric values (arithmetic, PROC MEANS, sort order,
NMISS/CMISS, cats()). Every claim was checked on a live SAS engine - the
sort order I first wrote down was wrong, ._ sorts below the regular missing.
- How they travel between the browser and SAS: the adapter's type inference,
the null handling, the format override for a column holding only special
missings, and the values it refuses.
- How they behave in the other Data Controller rules: NOTNULL passes, MINVAL
fails, MAXVAL passes, CASE compares them as text, and HARDREGEX/SOFTREGEX do
not exempt them.
The video embed was pointing at the right recording under the wrong label (a
copy-paste of "Retain Formulas when Loading Excel to SAS" from other posts).
It is "Managing Special Missing Values with Data Controller for SAS", and the
post now describes what it shows.
Also adds the LinkedIn version of the section as a comment, kept in sync with
the copy above.
The post claimed `smith` finds `Smithson`, which only holds for a case
insensitive match. The comparison is case sensitive, so the search term has
to match the case as stored: `Smith` finds `Smithson`, and `smith` finds
`Goldsmith`, but `smith` will not find `Smithson`.
dc