Method alias_with_metadata

datafusion/expr/src/expr.rs:1804–1810

Return `self AS name` alias expression with metadata The metadata will be attached to the Arrow Schema field when the expression is converted to a field via `Expr.to_field()`. # Example ``` # use datafusion_expr::col; # use std::collections::HashMap; # use datafusion_common::metadata::FieldMetadata; let metadata = HashMap::from([("key".to_string(), "value".to_string())]); let metadata = FieldMet

(
        self,
        name: impl Into<String>,
        metadata: Option<FieldMetadata>,
    )

    /// let expr = col("foo").alias_with_metadata("bar", Some(metadata));
    /// ```
    pub fn alias_with_metadata(
        self,
        name: impl Into<String>,
        metadata: Option<FieldMetadata>,
    ) -> Expr {
        Expr::Alias(Alias::new(self, None::<&str>, name.into()).with_metadata(metadata))
    }

    /// Return `self AS name` alias expression with a specific qualifier
    pub fn alias_qualified(