it.unibz.inf.ontop.dbschema.ForeignKeyConstraint Maven / Gradle / Ivy
package it.unibz.inf.ontop.dbschema;
import com.google.common.collect.ImmutableList;
import it.unibz.inf.ontop.dbschema.impl.ForeignKeyConstraintImpl;
/**
* Foreign Key constraints
*
* FOREIGN KEY (columnName (, columnName)*)
* REFERENCES refTableName (refColumnName (, refColumnName)*)
*
* (a particular case of linear tuple-generating dependencies
* \forall x (\exists y_1 R_1(x,y_1) \to \exists y_2 R_2(x,y_2))
* where x, y_1 and y_2 are *tuples* of variables)
*
* @author Roman Kontchakov
*/
public interface ForeignKeyConstraint {
interface Component {
Attribute getAttribute();
Attribute getReferencedAttribute();
}
interface Builder {
/**
* adds a pair (attribute, referenced attribute) to the FK constraint
*
* @param attributeIndex
* @param referencedAttributeIndex
* @return
*/
Builder add(int attributeIndex, int referencedAttributeIndex);
Builder add(QuotedID attributeId, QuotedID referencedAttributeId) throws AttributeNotFoundException;
/**
* builds a FOREIGN KEY constraint
*
* @throws IllegalArgumentException if the list of components is empty
*/
void build();
}
/**
* creates a FOREIGN KEY builder
*
* @param name
* @param relation
* @param referencedRelation
* @return
*/
static Builder builder(String name, NamedRelationDefinition relation, NamedRelationDefinition referencedRelation) {
return ForeignKeyConstraintImpl.builder(name, relation, referencedRelation);
}
/**
* creates a single-attribute foreign key
*/
static void of(String name, Attribute attribute, Attribute referencedAttribute) {
builder(name, (NamedRelationDefinition)attribute.getRelation(), (NamedRelationDefinition)referencedAttribute.getRelation())
.add(attribute.getIndex(), referencedAttribute.getIndex()).build();
}
/**
* returns the name of the foreign key constraint
*
* @return name
*/
String getName();
/**
* returns the components of the foreign key constraint
* each component defines a map from an attribute of the relation
* to an attribute of the referenced relation
*
* @return
*/
ImmutableList getComponents();
/**
* returns referenced database relation
*
* @return referenced relation
*/
NamedRelationDefinition getReferencedRelation();
/**
* returns the relation with the foreign key
*
* @return relation
*/
NamedRelationDefinition getRelation();
}