Loading arrayDS from sql select into statement?

I'm not real good at using sql set-at-a-time processing, so I'm hoping someone can give me some clues.

I'm okay with declaring cursors, and loading arrays with a multi-row fetch, or from "fetch next" inside a for-loop. I'm trying to improve my coding techniques, and understand the options.

I've seen mentions on this list of using "select into :ArrayDS", but whenever I try to code up such a thing, the sql precompiler says I can't - tells me my array is no good.
Specifically, "SQL0312: Position 16 Variable ArrayDS not defined or not usable."

I've tried all kinds of adjustments to simplify the host data structure to appease the precompiler, but it is not in the mood.

Compiling with CRTSQLRPGI on v7.1 with mostly up-to-date PTFs (I'm told). Could be missing one?
Or could be that I don't know what I'm doing. Or could be no one else can do this either?

Code that DOES NOT work:

DCL-DS ArrayDS QUALIFIED DIM(64);
userAcct CHAR(50);
END-DS ;

// dds-defined physical file SV02 has 3 records that meet "where" criteria.
// sv2eml is defined as character 50; sv2sts is defined as character 1.

exec sql
select sv2eml into :ArrayDS
from sv02
where sv2sts = '';

Is it just me ??? Thanks.
Michael Koester