如何使用自联接从单个表中检索数据

Question

我有这样的表

id     name     pid
101   Animal    null
102   Dog       101
103   pug       102

我想要动物＆gt;狗＆gt;哈巴狗

Answer 1

我认为这样的事情适合你，因为我不知道你的RDBMS可能需要一些改变

WITH  NewAnimal
        AS (SELECT  CAST((a.Desc + '>' + t.Name) AS VARCHAR(1000)) AS "Desc"
             FROM    Table AS t
             JOIN NewAnimal AS a
             ON t.PID = a.id
           )
SELECT * FROM NewAnimal