RelReferentialConstraint (Apache Calcite API)

All Known Implementing Classes:

RelReferentialConstraintImpl
```
public interface RelReferentialConstraint
```
Interface for a referential constraint, i.e., Foreign-Key - Unique-Key relationship, between two tables.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`java.util.List<IntPair>`	`getColumnPairs()`	The (source, target) column ordinals.
`int`	`getNumColumns()`	Returns the number of columns in the keys.
`java.util.List<java.lang.String>`	`getSourceQualifiedName()`	The qualified name of the referencing table, e.g.
`java.util.List<java.lang.String>`	`getTargetQualifiedName()`	The qualified name of the referenced table, e.g.

- Method Detail
  - getNumColumns
```
int getNumColumns()
```
    Returns the number of columns in the keys.
  - getSourceQualifiedName
```
java.util.List<java.lang.String> getSourceQualifiedName()
```
    The qualified name of the referencing table, e.g. DEPT.
  - getTargetQualifiedName
```
java.util.List<java.lang.String> getTargetQualifiedName()
```
    The qualified name of the referenced table, e.g. EMP.
  - getColumnPairs
```
java.util.List<IntPair> getColumnPairs()
```
    The (source, target) column ordinals.