Struct Scope 

pub struct Scope {
    pub using_columns: HashSet<String>,
    /* private fields */
}

A name scope for query resolution. Scopes nest for subqueries and CTEs.

Fields

using_columns: HashSet<String>

Columns that were joined via USING and are therefore unambiguous.

Implementations

impl Scope

pub fn root() -> Self

Create a root scope.

pub fn child(parent: Self) -> Self

Create a child scope (for subqueries).

pub fn add_alias( &mut self, alias: &str, table_name: &str, columns: Option<HashSet<String>>, )

Register a table alias with its columns.

pub fn add_qualified_only_alias( &mut self, alias: &str, table_name: &str, columns: Option<HashSet<String>>, )

Register an alias that does not participate in unqualified column resolution.

pub fn add_cte(&mut self, name: &str)

Register a CTE name.

pub fn has_cte(&self, name: &str) -> bool

Check if a CTE is visible in this scope (or parent scopes).

pub fn has_alias(&self, alias: &str) -> bool

Check if an alias is visible in this scope (or parent scopes).

pub fn has_alias_local(&self, alias: &str) -> bool

Check if an alias is defined locally in this scope.

pub fn resolve_column( &self, schema: &Schema, table_qualifier: Option<&str>, column_name: &str, ) -> ResolveResult

Resolve a column reference: find which alias provides it.

If table_qualifier is Some, checks only that alias. If None, searches all visible aliases for the column name. Returns the resolved (alias, column_name) or None.

pub fn alias_count(&self) -> usize

Number of aliases registered in this scope (not counting parents).

pub fn known_local_column_sets(&self) -> Vec<&HashSet<String>>

Return known column sets from all local aliases (for NATURAL JOIN). Aliases with unknown columns (None) are omitted.

pub fn columns_for_alias(&self, alias: &str) -> Option<&HashSet<String>>

Return the column set for a specific alias (lowercased lookup).

Trait Implementations

impl Clone for Scope

fn clone(&self) -> Scope

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Scope

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

Formats the value using the given formatter.