Struct GroupKeySpec 

pub struct GroupKeySpec {
    pub output_name: String,
    pub field: Option<String>,
    pub expr: Option<SqlExpr>,
}

A GROUP BY key specification for aggregate physical execution.

A bare-column key extracts its value from the document field named by field and emits it in the aggregate output row under output_name. For a plain column these are the same string. expr carries a computed-key expression to evaluate per row; it is always None for bare-column keys.

Fields

output_name: String

Output column name for this group key (alias, else the raw column name).

field: Option<String>

Bare-column extraction key. Some for a plain Column group key.

expr: Option<SqlExpr>

Computed-key expression, evaluated per row. None for bare-column keys.

Implementations

impl GroupKeySpec

pub fn column(name: impl Into<String>) -> Self

Build a bare-column group key: extract from name and emit under the same column name, with no computed expression.

Trait Implementations

impl Clone for GroupKeySpec

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 GroupKeySpec

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for GroupKeySpec

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'__msgpack_de> FromMessagePack<'__msgpack_de> for GroupKeySpec

fn read<R: Read<'__msgpack_de>>(reader: &mut R) -> Result<Self, Error>

where Self: Sized,

Reads the MessagePack representation of this value from the provided reader.

impl PartialEq for GroupKeySpec

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for GroupKeySpec

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for GroupKeySpec

impl ToMessagePack for GroupKeySpec

fn write<W: Write>(&self, writer: &mut W) -> Result<(), Error>

Writes the MessagePack representation of this value into the provided writer.

fn size_hint(&self) -> Option<TrustedSizeHint>

Returns a trusted upper bound for the number of bytes written by the next call to Self::write, or None when it cannot be determined cheaply.

fn max_size() -> Option<TrustedSizeHint>

Returns a trusted upper bound valid for every value of this type.

fn write_slice<W>(values: &[Self], writer: &mut W) -> Result<(), Error>

where W: Write, Self: Sized,

Writes the MessagePack representation of a slice of values into the provided writer.