Struct NestedProjection 

pub struct NestedProjection {
    pub name: String,
    pub table: String,
    pub alias: String,
    pub parent_alias: String,
    pub child_key: String,
    pub parent_key: String,
    pub residual: Option<Expr>,
    pub order: Vec<(String, bool)>,
    pub limit: Option<Expr>,
    pub offset: Option<Expr>,
    pub offset_before_limit: bool,
    pub fields: Vec<NestedField>,
}

The resolved form of one nested sub-query projection field. Correlation columns are pre-split by the planner: at the top level parent_key is the qualified parent column name (u.id) as produced by an AliasScan; for a nested-in-nested field it is the bare column name of the enclosing child table. child_key is always the bare child column name.

Fields

name: String

Output column name (the projection field’s alias).

table: String

alias: String

The child alias from the source text, kept for EXPLAIN and errors.

parent_alias: String

The enclosing scope’s alias, kept for EXPLAIN (the executor correlates through parent_key alone).

child_key: String

parent_key: String

residual: Option<Expr>

Residual filter conditions beyond the correlation predicate, rewritten by the planner to reference bare child columns.

order: Vec<(String, bool)>

Per-parent ordering: (bare child column, descending) keys applied to each parent’s child bucket before truncation.

limit: Option<Expr>

Per-parent truncation bounds, applied after ordering. Must evaluate to non-negative integer literals (like top-level limit/offset).

offset: Option<Expr>

offset_before_limit: bool

Source wrote offset before limit; the plan cache refuses this form (see plan_cache::nested_projection_defeats_cache).

fields: Vec<NestedField>

Implementations

impl NestedProjection

pub fn visit_tables(&self, visit: &mut dyn FnMut(&str))

Visit this projection’s child table and every deeper nested child table. Used for dirty-view escalation and auto-refresh.

Trait Implementations

impl Clone for NestedProjection

fn clone(&self) -> NestedProjection

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for NestedProjection

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

Formats the value using the given formatter.