Native Jet tables are updateable if the database is not open in a read only
mode,
A query is not updateable (not an exhaustive list)
- it has UNION (even UNION ALL is not updateable)
- it has GROUP ( or an aggregate, like SUM, MIN, MAX, COUNT ... or
DISTINCT, or TRANSFORM )
- it uses a not updateable query (else than in the WHERE clause)
- it uses a non-equi join
and in many occasions, it requires a primary key.
Basically, if you cannot track back which UNIQUE record has to be modified,
back in the table, then it is not updateable. There are also 'short-cut' due
to implementations which make a Jet query not updateable, like
UPDATE table1
SET field1 = (SELECT SUM(field2) FROM table2)
but then, you can use:
UPDATE table1
SET field1 = DSUM("field2", "table2")
Vanderghast, Access MVP
