加入重复列名的结果 'year'

Question

我想要这样的东西（工作示例）：

SELECT DISTINCT year FROM
    (SELECT year FROM classbook WHERE year > 1
        UNION ALL SELECT year + 1 as year FROM classbook WHERE year > 1) qu
ORDER BY year

我试过了：

SELECT DISTINCT year FROM
    (SELECT year, year + 1 as year FROM classbook WHERE year > 1) qu
ORDER BY year

但这会抛出 Duplicate column name 'year'。

完成此操作的最简单（更简单）的方法是什么？

我正在使用 MySQL 数据库。

Answer 1

您的第一个查询没问题。您不需要子查询：

SELECT year
FROM classbook
WHERE year > 1
UNION   -- on purpose to remove duplicates
SELECT year + 1 as year
FROM classbook
WHERE year > 1
ORDER BY year

加入重复列名的结果 'year'

Join results of Duplicate column name 'year'

mysql

sql

select

subquery