Method try_as_col

datafusion/expr/src/expr.rs:2021–2027

Return a reference to the inner `Column` if any returns `None` if the expression is not a `Column` Note: None may be returned for expressions that are not `Column` but are convertible to `Column` such as `Cast` expressions. Example ``` # use datafusion_common::Column; use datafusion_expr::{col, Expr}; let expr = col("foo"); assert_eq!(expr.try_as_col(), Some(&Column::from("foo"))); let expr =

(&self)

    /// assert_eq!(expr.try_as_col(), None);
    /// ```
    pub fn try_as_col(&self) -> Option<&Column> {
        if let Expr::Column(it) = self {
            Some(it)
        } else {
            None
        }
    }

    /// Returns the inner `Column` if any. This is a specialized version of
    /// [`Self::try_as_col`] that take Cast expressions into account when the