Hi,
You can't since DDL means Data Definition Language and is used to
define a table, as example, while DML is for Manipulation of the data.
A self join is any kind of join where the table is joined with itself
(as in the case of a hierarchy), etc.
You don't use DDL, DML, neither SELF. Alias, in the other hand, is
generally introduced with the keyword AS, not with ALIAS.
Hoping it may help,
Vanderghast, Access MVP