Enum FieldSource 

pub enum FieldSource {
    Column(Column),
    Group(Vec<Field>),
    Geo(Geo),
    Relation(Relation),
    Constant(GenericValue),
}

Where a field’s value comes from. The shapes are mutually exclusive — a field is exactly one of them — which is why this is an enum rather than a bag of optional column / relation / fields that can contradict each other.

Variants

Column(Column)

A column of the current row, optionally transformed, with an optional fallback when the column is null.

Group(Vec<Field>)

A sub-object assembled from sibling fields of the same row (it adds a nesting level in the document without reading a related table).

Geo(Geo)

A geographic point assembled from two same-row columns (lat/lon) into an OpenSearch geo_point.

Relation(Relation)

Data drawn from a related table — folded in as nested documents (Join) or reduced to a single value (Aggregate).

Constant(GenericValue)

A constant value with no database source — None renders as null.

Trait Implementations

impl Clone for FieldSource

fn clone(&self) -> FieldSource

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FieldSource

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for FieldSource

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for FieldSource

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

where __H: Hasher,

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 Serialize for FieldSource

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

where __S: Serializer,

Serialize this value into the given Serde serializer.