Struct mz_repr::relation::RelationType

pub struct RelationType {
    pub column_types: Vec<ColumnType>,
    pub keys: Vec<Vec<usize>>,
}

The type of a relation.

Fields

column_types: Vec<ColumnType>

The type for each column, in order.

keys: Vec<Vec<usize>>

Sets of indices that are “keys” for the collection.

Each element in this list is a set of column indices, each with the property that the collection contains at most one record with each distinct set of values for each column. Alternately, for a specific set of values assigned to the these columns there is at most one record.

A collection can contain multiple sets of keys, although it is common to have either zero or one sets of key indices.

Implementations

impl RelationType

pub fn empty() -> Self

Constructs a RelationType representing the relation with no columns and no keys.

pub fn new(column_types: Vec<ColumnType>) -> Self

Constructs a new RelationType from specified column types.

The RelationType will have no keys.

pub fn with_key(self, indices: Vec<usize>) -> Self

Adds a new key for the relation.

pub fn with_keys(self, keys: Vec<Vec<usize>>) -> Self

pub fn arity(&self) -> usize

Computes the number of columns in the relation.

pub fn default_key(&self) -> Vec<usize>

Gets the index of the columns used when creating a default index.

pub fn subtypes(&self, other: &RelationType) -> bool

True if any collection described by self could safely be described by other.

In practice this means checking that the scalar types match exactly, and that the nullability of self is at least as strict as other, and that all keys of other contain some key of self (as a set of key columns is less strict than any subset).

Trait Implementations

impl Arbitrary for RelationType

type Parameters = (<Vec<ColumnType, Global> as Arbitrary>::Parameters, <Vec<Vec<usize, Global>, Global> as Arbitrary>::Parameters)

The type of parameters that arbitrary_with accepts for configuration of the generated Strategy. Parameters must implement Default.

type Strategy = Map<(<Vec<ColumnType, Global> as Arbitrary>::Strategy, <Vec<Vec<usize, Global>, Global> as Arbitrary>::Strategy), fn(_: (Vec<ColumnType, Global>, Vec<Vec<usize, Global>, Global>)) -> RelationType>

The type of Strategy used to generate values of type Self.

fn arbitrary_with(_top: Self::Parameters) -> Self::Strategy

Generates a Strategy for producing arbitrary values of type the implementing type (Self). The strategy is passed the arguments given in args.

fn arbitrary() -> Self::Strategy

Generates a Strategy for producing arbitrary values of type the implementing type (Self).

impl Clone for RelationType

fn clone(&self) -> RelationType

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for RelationType

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for RelationType

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for RelationType

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl MzReflect for RelationType

fn add_to_reflected_type_info(rti: &mut ReflectedTypeInfo)

Adds names and types of the fields of the struct or enum to rti.

impl Ord for RelationType

fn cmp(&self, other: &RelationType) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl PartialEq<RelationType> for RelationType

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd<RelationType> for RelationType

fn partial_cmp(&self, other: &RelationType) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl RustType<ProtoRelationType> for RelationType

fn into_proto(&self) -> ProtoRelationType

Convert a Self into a Proto value.

fn from_proto(proto: ProtoRelationType) -> Result<Self, TryFromProtoError>

Consume and convert a Proto back into a Self value.

impl Serialize for RelationType

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for RelationType

impl StructuralEq for RelationType

impl StructuralPartialEq for RelationType