Function col

datafusion/expr/src/expr_fn.rs:68–70

Create a column expression based on a qualified or unqualified column name. Will normalize unquoted identifiers according to SQL rules (identifiers will become lowercase). For example: ```rust # use datafusion_expr::col; let c1 = col("a"); let c2 = col("A"); assert_eq!(c1, c2); // note how quoting with double quotes preserves the case let c3 = col(r#""A""#); assert_ne!(c1, c3); ```

(ident: impl Into<Column>)

/// assert_ne!(c1, c3);
/// ```
pub fn col(ident: impl Into<Column>) -> Expr {
    Expr::Column(ident.into())
}

/// Create an out reference column which hold a reference that has been resolved to a field
/// outside of the current plan.