Function translate_select_item

prqlc/prqlc/src/sql/gen_expr.rs:781–808

(cid: rq::CId, ctx: &mut Context)

}

pub(super) fn translate_select_item(cid: rq::CId, ctx: &mut Context) -> Result<SelectItem> {
    let expr = translate_cid(cid, ctx)?.into_ast();

    let inferred_name = match &expr {
        // sql_ast::Expr::Identifier is used for s-strings
        sql_ast::Expr::CompoundIdentifier(parts) => parts.last().map(|p| &p.value),
        _ => None,
    }
    .filter(|n| *n != "*");

    let expected = ctx.anchor.column_names.get(&cid);

    if inferred_name != expected {
        // use expected name
        let ident = expected.cloned().unwrap_or_else(|| {
            // or use something that will not clash with other names
            ctx.anchor.col_name.gen()
        });
        ctx.anchor.column_names.insert(cid, ident.to_string());

        return Ok(SelectItem::ExprWithAlias {
            alias: translate_ident_part(ident, ctx),
            expr,
        });
    }

    Ok(SelectItem::UnnamedExpr(expr))
}

fn translate_windowed(
    expr: ExprOrSource,