Function test_transform_bottom_unnest

datafusion/sql/src/utils.rs:841–935

()

    #[test]
    fn test_transform_bottom_unnest() -> Result<()> {
        let schema = Schema::new(vec![
            Field::new(
                "struct_col",
                ArrowDataType::Struct(Fields::from(vec![
                    Field::new("field1", ArrowDataType::Int32, false),
                    Field::new("field2", ArrowDataType::Int32, false),
                ])),
                false,
            ),
            Field::new(
                "array_col",
                ArrowDataType::List(Arc::new(Field::new_list_field(
                    ArrowDataType::Int64,
                    true,
                ))),
                true,
            ),
            Field::new("int_col", ArrowDataType::Int32, false),
        ]);

        let dfschema = DFSchema::try_from(schema)?;

        let input = LogicalPlan::EmptyRelation(EmptyRelation {
            produce_one_row: false,
            schema: Arc::new(dfschema),
        });

        let mut unnest_placeholder_columns = IndexMap::new();
        let mut inner_projection_exprs = vec![];

        // unnest(struct_col)
        let original_expr = unnest(col("struct_col"));
        let transformed_exprs = rewrite_recursive_unnest_bottom_up(
            &input,
            &mut unnest_placeholder_columns,
            &mut inner_projection_exprs,
            &original_expr,
        )?;
        assert_eq!(
            transformed_exprs,
            vec![
                col("__unnest_placeholder(struct_col).field1"),
                col("__unnest_placeholder(struct_col).field2"),
            ]
        );
        column_unnests_eq(
            vec!["__unnest_placeholder(struct_col)"],
            &unnest_placeholder_columns,
        );
        // Still reference struct_col in original schema but with alias,
        // to avoid colliding with the projection on the column itself if any
        assert_eq!(
            inner_projection_exprs,
            vec![col("struct_col").alias("__unnest_placeholder(struct_col)"),]
        );

        // unnest(array_col) + 1