可以在没有关系的情况下加入2张桌子吗？

Question

我有一个要求，我有两个不相关的数据表，但我需要为 APEX 报告的每个

FORM

记录列出所有

STUDENT

记录。我对连接进行了搜索，发现最接近的是

FULL OUTER JOIN

，但这依赖于连接列。我正在使用 Oracle 19c。

TBL_FORMS

FORM_ID | FORM_NAME      | ITEM_NAME
==============================================
1       | Favorite Color | Blue
1       | Favorite Color | Green

TBL_学生

STUDENT_ID | STUDENT_NAME | STUDENT_GRADE
=========================================
1          | John         | 1
2          | Sally        | 4

期望的结果

STUDENT_ID | STUDENT_NAME | STUDENT_GRADE | FORM_ID | FORM_NAME      | ITEM_NAME
=======================================================================================
1          | John         | 1             | 1       | Favorite Color | Blue
1          | John         | 1             | 1       | Favorite Color | Green
2          | Sally        | 4             | 1       | Favorite Color | Blue
2          | Sally        | 4             | 1       | Favorite Color | Green

Answer 1

如果一个表的每一行都应与另一个表的每一行相关，那么您需要一个

CROSS JOIN

:

SELECT *
FROM   tbl_forms
       CROSS JOIN tbl_students;