我正在完成 HackerRank 挑战，但文档说我不应该使用 AS 关键字：
我需要在 MySQL 中重写此查询，以便它不包含 WITH A AS 中的 AS，也不包含 SELECT...AS test 中的 AS
WITH A AS (
SELECT DISTINCT
MAX( LENGTH( customer_id ) ) AS test
FROM
orders
UNION
SELECT DISTINCT
MIN( LENGTH( customer_id ) )
FROM
orders
)
SELECT
test,
LENGTH(test)
FROM
A
WITH 子句用于声明 VIEW，因此您可以像下面这样重写它
SELECT test, LENGTH(test) FROM ( SELECT DISTINCT MAX( LENGTH( customer_id ) ) AS test FROM orders UNION SELECT DISTINCT MIN( LENGTH( customer_id ) ) FROM orders)