Function form_identifier

datafusion/sql/src/expr/identifier.rs:282–308

(relation, column name)

(idents: &[String])

// (relation, column name)
fn form_identifier(idents: &[String]) -> Result<(Option<TableReference>, &String)> {
    match idents.len() {
        1 => Ok((None, &idents[0])),
        2 => Ok((
            Some(TableReference::Bare {
                table: idents[0].clone().into(),
            }),
            &idents[1],
        )),
        3 => Ok((
            Some(TableReference::Partial {
                schema: idents[0].clone().into(),
                table: idents[1].clone().into(),
            }),
            &idents[2],
        )),
        4 => Ok((
            Some(TableReference::Full {
                catalog: idents[0].clone().into(),
                schema: idents[1].clone().into(),
                table: idents[2].clone().into(),
            }),
            &idents[3],
        )),
        _ => internal_err!("Incorrect number of identifiers: {}", idents.len()),
    }
}

fn search_dfschema<'ids, 'schema>(
    ids: &'ids [String],