sql - Oracle 给定的列名

Question

我有 2 个表，其中包含 2 列(user_id 和年份)。

查询 1:

SELECT * FROM table_1 t1 
FULL JOIN table_2 t2 ON t1.user_id=t2.user_id AND t1.year=t2.year

产生以下列名称:

user_id, year, user_id_1, year_1

查询2:

CREATE TABLE table_copy AS SELECT * FROM
(SELECT * FROM table_1 t1 
 FULL JOIN table_2 t2 ON t1.user_id=t2.user_id  AND t1.year=t2.year);

产生以下模糊的列名:

QCSJ_C000000000400000, QCSJ_C000000000400002, QCSJ_C000000000400001, QCSJ_C000000000400003

有没有一种简短的方法可以强制 Oracle query2 使用与 query1 相同的名称而不显式写入它们(当有很多列时很重要)？也许是一些 Oracle 设置？

Answer 1

列出您的列并使用 AS 指定列名。

例如

CREATE TABLE table_copy AS
SELECT t1.user_id AS t1_user_id,
       t1.year    AS t1_year,
       t2.user_id AS t2_user_id,
       t2.year    AS t2_year
FROM   table_1 t1
FULL   JOIN table_2 t2 ON t1.user_id=t2.user_id
AND    t1.year=t2.year;