Enum Projection 

pub enum Projection {
    All,
    Column(String),
    Alias(String, String),
    Function(String, Vec<Projection>),
    Expression(Box<Filter>, Option<String>),
    Field(FieldRef, Option<String>),
}

Column/field projection

Variants

All

Select all columns (*)

Column(String)

Single column by name

Alias(String, String)

Column with alias

Function(String, Vec<Projection>)

Function call (name, args)

Expression(Box<Filter>, Option<String>)

Expression with optional alias

Field(FieldRef, Option<String>)

Field reference (for graph properties)

Implementations

impl Projection

pub fn from_field(field: FieldRef) -> Projection

Create a projection from a field reference

pub fn column(name: &str) -> Projection

Create a column projection

pub fn with_alias(column: &str, alias: &str) -> Projection

Create an aliased projection

Trait Implementations

impl Clone for Projection

fn clone(&self) -> Projection

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Projection

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

Formats the value using the given formatter.

impl PartialEq for Projection

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl StructuralPartialEq for Projection