Class: TMMUpdater
property Where : string;Optional additional WHERE condition for
umUpdate, appended with AND after the
automatic PK predicate.
Supports :param placeholders resolved from the Params
collection. Ignored for umInsert and
umUpsert.
When to use it: - Additional static filter applied
to every row in the batch, e.g. 'region = :region' with
Params.ParamByName('region').AsString := 'EU'. -
Required when the target table has no PRIMARY KEY – in
that case it is the sole WHERE source and must identify the target
rows.
When NOT to use it: Do not use Where to
route PK columns to the WHERE clause.
The server detects the PRIMARY KEY automatically and routes PK columns
to WHERE.
Prepare also force-includes PK columns in the buffer
regardless of UpdateColumns,
so you do not need to list them explicitly.
Leave Where empty for standard PK-based updates.