python - PySpark:如何在 rdd join 期间从左表中选择 *

Question

如何在pyspark join中选择*

impression_rdd.join(
        click_rdd, 
        impression_rdd.session_id == click_rdd.session_id, 
        "left_outer"
    ).select(impression_rdd.*) <------- pseudo code; how do you do this?

基本上，sql 等价物

SELECT impression.* FROM impression LEFT JOIN click on (impression.session_id = click.session_id)

Answer 1

您可以简单地在您的伪代码中添加别名和几个引号:

(impressions.alias("impressions")
    .join(clicks, ["id"], "left_outer")
    .select("impressions.*"))