Struct mz_repr::relation::ColumnType

pub struct ColumnType {
    pub scalar_type: ScalarType,
    pub nullable: bool,
}

The type of a Datum.

ColumnType bundles information about the scalar type of a datum (e.g., Int32 or String) with its nullability.

To construct a column type, either initialize the struct directly, or use the ScalarType::nullable method.

Fields

scalar_type: ScalarType

The underlying scalar type (e.g., Int32 or String) of this column.

nullable: bool

Whether this datum can be null.

Implementations

impl ColumnType

pub fn union(&self, other: &Self) -> Result<Self, Error>

pub fn nullable(self, nullable: bool) -> Self

Consumes this ColumnType and returns a new ColumnType with its nullability set to the specified boolean.

impl ColumnType

pub fn to_persist<R, F: DatumToPersistFn<R>>(&self, f: F) -> Option<R>

Returns the DatumToPersist implementation for this ColumnType.

See DatumToPersist to map Datums to/from a persist columnar type. There is a 1:N correspondence between DatumToPersist impls and ColumnTypes because a number of ScalarTypes map to the same set of Datums (e.g. String and VarChar).

This returns a None if we don’t care to keep stats for this column type (for now). We’ll have to remove this if/when we start actually using the schema’d part encoding.

Trait Implementations

impl Arbitrary for ColumnType

type Parameters = (<ScalarType as Arbitrary>::Parameters, <bool as Arbitrary>::Parameters)

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

type Strategy = Map<(<ScalarType as Arbitrary>::Strategy, <bool as Arbitrary>::Strategy), fn(_: (ScalarType, bool)) -> ColumnType>

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 ColumnType

fn clone(&self) -> ColumnType

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnType

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for ColumnType

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

Deserialize this value from the given Serde deserializer.

impl Display for ColumnType

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

Formats the value using the given formatter.

impl Hash for ColumnType

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 ColumnType

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 ColumnType

fn cmp(&self, other: &ColumnType) -> 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,

Restrict a value to a certain interval.

impl PartialEq for ColumnType

fn eq(&self, other: &ColumnType) -> 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 for ColumnType

fn partial_cmp(&self, other: &ColumnType) -> 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<ProtoColumnType> for ColumnType

fn into_proto(&self) -> ProtoColumnType

Convert a Self into a Proto value.

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

Consume and convert a Proto back into a Self value.

impl Serialize for ColumnType

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 ColumnType

impl StructuralEq for ColumnType

impl StructuralPartialEq for ColumnType