Struct ProjectionField 

pub struct ProjectionField {
    pub name: String,
    pub source: String,
    pub kind: FieldKind,
    pub sub_fields: Option<Vec<ProjectionField>>,
}

A field in a SQL projection with type information.

Used by typed projection generators to choose the correct JSONB extraction operator based on FieldKind: -> (preserves JSONB) for composites and native scalars, ->> (text) for text scalars (String, ID).

When sub_fields is populated on a composite field, generate_typed_projection_sql will recurse and emit a nested jsonb_build_object(...) instead of returning the full composite blob. Leave sub_fields as None to get the existing data->'field' behaviour (full blob, no sub-selection).

Fields

name: String

Output (response) key — the GraphQL alias if present, otherwise the field name. Used verbatim as the key in the generated jsonb_build_object.

source: String

Source GraphQL field name (camelCase) used to derive the JSONB column via to_snake_case. Equals name for unaliased fields, but differs when the field is aliased: myName: fullName yields name = "myName", source = "fullName", so the projection reads data->>'full_name' while emitting it under the myName key (#418).

kind: FieldKind

Semantic kind of the field, controlling the JSONB extraction operator.

sub_fields: Option<Vec<ProjectionField>>

Sub-fields to project for composite (Object) types.

When Some and non-empty, the generator recurses and produces a nested jsonb_build_object instead of returning the entire composite blob. Set to None (or Some([])) to fall back to data->'field'. List fields should always use None — sub-projection inside aggregated JSONB arrays is out of scope for this first iteration.

Implementations

impl ProjectionField

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

Create a text scalar projection field (uses ->> text extraction).

Use for String and ID fields only. Other scalars (Int, Float, Boolean, DateTime, etc.) should use Self::native.

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

Create a native JSON scalar projection field (uses -> to preserve type).

Use for Int, Float, Boolean, DateTime, Date, Time, Decimal, Vector, and other non-text scalars. ->> would coerce these to strings inside jsonb_build_object, losing type information.

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

Create a composite (object/list) projection field (uses -> JSONB extraction).

pub fn composite_with_sub_fields( name: impl Into<String>, sub_fields: Vec<Self>, ) -> Self

Create a composite projection field with known sub-fields.

The generator will recurse into sub_fields and emit a nested jsonb_build_object(...) rather than returning the full composite blob.

pub const fn is_composite(&self) -> bool

Whether this field is a composite type (Object or List).

Trait Implementations

impl Clone for ProjectionField

fn clone(&self) -> ProjectionField

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ProjectionField

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

Formats the value using the given formatter.

impl Eq for ProjectionField

impl From<String> for ProjectionField

fn from(name: String) -> Self

Converts to this type from the input type.

impl PartialEq for ProjectionField

fn eq(&self, other: &ProjectionField) -> 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 ProjectionField