Struct Aggregate 

pub struct Aggregate {
    pub table: TableName,
    pub op: AggregateOp,
    pub key: AggregateKey,
    pub value_type: Option<FlussoType>,
    pub filters: Option<Vec<Filter>>,
    pub distinct: bool,
    pub via: Vec<ViaHop>,
    pub on: Vec<ColumnPair>,
}

Reduces rows from a related table to a single value — a count, sum, extreme, or existence flag. The key connects the tables; filters restrict which rows of table count; via reaches table across the tables in between.

Fields

table: TableName

op: AggregateOp

key: AggregateKey

value_type: Option<FlussoType>

The declared result type. Fixed for count (long) and avg (double) and left None; required for sum / min / max, whose result mirrors the aggregated column and so must be stated to stay database-free.

filters: Option<Vec<Filter>>

distinct: bool

Over a junction: count each target row once instead of once per junction row. Only valid with an AggregateKey::Through key.

via: Vec<ViaHop>

The tables between the parent and table, in order from the parent. Empty for a one-hop aggregate. When set, the key points at the last hop’s table instead of the parent.

on: Vec<ColumnPair>

Extra column equalities between the aggregated rows and the table before them (the parent, or the last via hop), ANDed with the key. Only with an AggregateKey::Direct key.

Trait Implementations

impl Clone for Aggregate

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 Aggregate

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Aggregate

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for Aggregate

Hashes distinct only when set and via/on only when non-empty, so a schema that never opts in keeps the content hash (and so the physical index) it had before the fields existed.

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 Serialize for Aggregate

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

where __S: Serializer,

Serialize this value into the given Serde serializer.