SQL::ReferentialUpdateRule Enumerated Type
This is an enumerated type is used to describe desired behavior when an update or a delete occurs for a table that has references to it from one or more other tables. The value is specified as an update or delete rule for a specific reference (foreign key relationship) and is a constraint on the referencing table. The values in the following list are supported:
Dim Index as SQL::IndexInfo Index.ReferencedTable = MyReferencedTable ? Index.DeleteRule = SetNull Index.UpdateRule = Cascade
The resulting create table statements. Note the italicized ON clauses in the second table.
CREATE TABLE MyReferencedTable ( Key1 VARCHAR NOT NULL, ? PRIMARY KEY (Key1) ) CREATE TABLE MyReferencingTable ( Key1 VARCHAR(5) NOT NULL, Key2 VARCHAR(5) NOT NULL, ? PRIMARY KEY (Key1, Key2), FOREIGN KEY (Key1) REFERENCES MyReferencedTable ON DELETE SET NULL ON UPDATE CASCADE )
Internal use only.