Use of Table Tags when Deleting
Not all databases support use of table tags in
DELETE SQL statements. DB Access Modules for databases take care of this internally so that
RWDBDeleter produces a
DELETE SQL with or without table tags, depending on that particular Access Module. The use of table tags by each of the Access Modules is documented in the Access Module User's Guides.
Correlated deletes, explained in
Subqueries and Correlated Deletes, contain subqueries that reference the table being updated. If a particular Access Module does not support use of table tags in
RWDBDeleter, the column name in the correlated subquery referencing the table being modified may still get qualified by using the table tag. This can be prevented by clearing the tag on the table being modified. In the above example:
RWDBTable primary = myDbase.table("primary");
primary.tag("");
