对多个值进行分组的 SQL 查询

Question

你能告诉我如何为以下要求构建 sql 查询吗：我有 2 个表：

表一：

col1 | Col2
------------
1    | a
2    | b

表 B：

Col1 | Col2
-----------
1    | 10
2    | 20
a    | 30
b    | 40

我需要这样的输出：

Col1 | Col2
------------
1,a  | 10,30
2,b  | 20,40

任何人都可以帮助我。 谢谢

Answer 1

你可以使用这个：

SELECT CONCAT(t1.col1, ' , ', t2.col1) AS Col1, CONCAT(t1.col2, ' , ', t2.col2) AS Col2
from
(select t1.col1, t2.col2 from tableA t1, tableB t2
where t1.col1 = t2.col1) as t1,
(select t1.col1 as col3, t2.col1, t2.col2 from tableA t1, tableB t2
where t1.col2 = t2.col1) as t2
where t1.col1 = t2.col3;

SQL小提琴在这里： http ://sqlfiddle.com/#!9/459ae69/25

Answer 2

SQL 演示

SELECT  CONCAT(CONCAT(A."Col1", ' , '), A."Col2") AS Col1, 
        LISTAGG(B."Col2", ', ') WITHIN GROUP (ORDER BY B."Col1") Col2
FROM TableA A
JOIN TableB B
  ON A."Col1" = B."Col1"
  OR A."Col2" = B."Col1"
GROUP BY CONCAT(CONCAT(A."Col1", ' , '), A."Col2")  
  ;

输出

|  COL1 |   COL2 |
|-------|--------|
| 1 , a | 10, 30 |
| 2 , b | 20, 40 |