Method alias_qualified_with_metadata

datafusion/expr/src/expr.rs:1836–1843

Return `self AS name` alias expression with a specific qualifier and 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())])

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

    ///     col("foo").alias_qualified_with_metadata(Some("tbl"), "bar", Some(metadata));
    /// ```
    pub fn alias_qualified_with_metadata(
        self,
        relation: Option<impl Into<TableReference>>,
        name: impl Into<String>,
        metadata: Option<FieldMetadata>,
    ) -> Expr {
        Expr::Alias(Alias::new(self, relation, name.into()).with_metadata(metadata))
    }

    /// Remove an alias from an expression if one exists.
    ///