Struct ScopedTable 

pub struct ScopedTable {
    pub table: Arc<TableMetadata>,
    pub start_index: usize,
    pub scope_level: usize,
    pub hidden_unqualified_columns: HashSet<String>,
    pub merged_column_partners: HashMap<String, Vec<usize>>,
    /* private fields */
}

A table visible to expression name resolution.

The metadata is shared rather than owned: every enclosing scope is copied into each nested scope, and copying whole schemas there made resolution cost grow with the square of the nesting depth.

Fields

table: Arc<TableMetadata>

start_index: usize

scope_level: usize

Lexical nesting level; zero is the current SELECT and larger values are successively enclosing SELECT scopes.

hidden_unqualified_columns: HashSet<String>

Columns coalesced by a JOIN … USING or NATURAL JOIN. They remain addressable by a qualified right-hand reference, but are not candidates for an unqualified reference because the merged output column owns the name.

merged_column_partners: HashMap<String, Vec<usize>>

For a column merged by USING or NATURAL, the output indexes of every other side. An unqualified reference to a merged name resolves to COALESCE(left, right, ...) so that RIGHT and FULL joins report the key from whichever joined input is present.

Implementations

impl ScopedTable

pub fn new(table: impl Into<Arc<TableMetadata>>, start_index: usize) -> Self

pub fn column_position(&self, column: &str) -> Option<usize>

Position of column in this table, or None if it has no such column.

pub fn hide_unqualified_columns(&mut self, columns: &[String])

pub fn merge_column_with(&mut self, column: &str, partner_index: usize)

Record that column is merged with the output column at partner_index.

Trait Implementations

impl Clone for ScopedTable

fn clone(&self) -> ScopedTable

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ScopedTable

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

Formats the value using the given formatter.