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| Alzabo::ForeignKey(3) | User Contributed Perl Documentation | Alzabo::ForeignKey(3) |
NAME
Alzabo::ForeignKey - Foreign key (relation) objectsSYNOPSIS
use Alzabo::ForeignKey;
foreach my $fk ($table->foreign_keys)
{
print $fk->cardinality;
}
DESCRIPTION
A foreign key is an object defined by several properties. It represents a relationship from a column or columns in one table to a column or columns in another table.This relationship is defined by its cardinality (one to one, one to many, or many to one) and its dependencies (whether or not table X is dependent on table Y, and vice versa).
Many to many relationships are not allowed. However, you may indicate such a relationship when using the Alzabo::Create::Schema->add_relation method method, and it will create the necessary intermediate linking table for you.
METHODS
table_from
table_to
Returns the relevant "Alzabo::Table" object.columns_from
columns_to
Returns the relevant "Alzabo::Column" object(s) for the property as an array.column_pairs
Returns an array of array references. The references are to two column array of "Alzabo::Column" objects. These two columns correspond in the tables being linked together.cardinality
Returns a two element array containing the two portions of the cardinality of the relationship. Each portion will be either '1' or 'n'.from_is_dependent
to_is_dependent
Returns a boolean value indicating whether there is a dependency from one table to the other.is_one_to_one
is_one_to_many
is_many_to_one
Returns a boolean value indicating what kind of relationship the object represents.is_same_relationship_as ($fk)
Given a foreign key object, this returns true if the two objects represent the same relationship. However, the two objects may represent the same relationship from different table's points of view.id
Returns a string uniquely identifying the foreign key.comment
Returns the comment associated with the foreign key object, if any.AUTHOR
Dave Rolsky, <autarch@urth.org>| 2022-04-07 | perl v5.32.1 |
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