Struct Relationship 

pub struct Relationship {
    pub child: Side,
    pub parent: Side,
    pub cardinality: Cardinality,
}

A declared many-to-one relationship from a child table to a parent table.

Fields

child: Side

The many side, which is where the forward link lives.

parent: Side

The one side, which is where the key map lives.

cardinality: Cardinality

What the build observed, or Cardinality::Unverified before it ran.

Implementations

impl Relationship

pub fn declare(child: Side, parent: Side) -> Result<Self>

A relationship not yet verified, which is what a declaration produces.

Errors

If the two sides have different numbers of key columns, or if a side names a table as its own parent through the same columns. The first is a declaration that cannot be equated column by column. The second is a self relationship on identical columns, which is the identity and carries no information.

pub fn name(&self) -> String

The name this relationship reports under in rudb_links().

Derived rather than given, because section 2.3 names a relationship by what it relates and there is nowhere in the graph_links grammar for an author to supply a name. A derived name is also stable across a reload, which is what lets a query log entry from yesterday still name a relationship today.

pub fn single_column(&self) -> bool

Whether the two sides are keyed on one column each.

Trait Implementations

impl Clone for Relationship

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Relationship

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Relationship

fn fmt(&self, formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Relationship

impl PartialEq for Relationship

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Relationship