#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Select {
    pub projection: Vec<SelectItem>,
    pub from: String,
    pub selection: Option<Expr>,
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub enum SelectItem {
    Wildcard,
    Expr { expr: Expr, alias: Option<String> },
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub enum Expr {
    Identifier(String),
    Literal(Literal),
    Binary {
        left: Box<Expr>,
        op: BinaryOp,
        right: Box<Expr>,
    },
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub enum Literal {
    String(String),
    Null,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum BinaryOp {
    Eq,
}