Struct ProjectedColumn 

pub struct ProjectedColumn {
    pub expr: TypedExpr,
    pub alias: Option<String>,
}

A projected column for SELECT clauses.

Contains a typed expression and an optional alias.

Examples

use alopex_sql::planner::typed_expr::{ProjectedColumn, TypedExpr, TypedExprKind};
use alopex_sql::planner::types::ResolvedType;
use alopex_sql::Span;

// SELECT name AS user_name
let projected = ProjectedColumn {
    expr: TypedExpr {
        kind: TypedExprKind::ColumnRef {
            table: "users".to_string(),
            column: "name".to_string(),
            column_index: 1,
        },
        resolved_type: ResolvedType::Text,
        span: Span::default(),
    },
    alias: Some("user_name".to_string()),
};

Fields

expr: TypedExpr

The projected expression.

alias: Option<String>

Optional alias (AS name).

Implementations

impl ProjectedColumn

pub fn new(expr: TypedExpr) -> Self

Creates a new projected column without an alias.

pub fn with_alias(expr: TypedExpr, alias: String) -> Self

Creates a new projected column with an alias.

pub fn output_name(&self) -> Option<&str>

Returns the output name (alias if present, otherwise derived from expression).

Returns:

• The alias if one was specified (e.g., SELECT name AS user_name)
• The column name for simple column references (e.g., SELECT name)
• None for complex expressions without an alias (e.g., SELECT 1 + 2)

Complex expressions (function calls, literals, binary operations) return None because they don’t have a natural name. Use with_alias to give them an output name.

Trait Implementations

impl Clone for ProjectedColumn

fn clone(&self) -> ProjectedColumn

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ProjectedColumn

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

Formats the value using the given formatter.