oracle解决关联查询报invalid number问题

出现问题的原因和背景

oracle进行关联查询的时候因为字段存在多个用逗号切割的id，导致查询的过程中报无效数字或非法数字

问题复现

新建表A

CREATE TABLE  "A" (
  id NUMBER NOT NULL,
  name VARCHAR2(255 BYTE)
)

INSERT INTO "A" VALUES ('1', '上海');
INSERT INTO "A" VALUES ('2', '北京');
INSERT INTO "A" VALUES ('3', '广州');
INSERT INTO "A" VALUES ('4', '深圳');

新建表B

CREATE TABLE  "B" (
  id NUMBER NOT NULL,
  aid VARCHAR2(255 BYTE)
)

INSERT INTO "B" VALUES ('1', '1,2,3');
INSERT INTO "B" VALUES ('2', '1,2');
INSERT INTO "B" VALUES ('3', '1,2,3,4');

问题复现

select * from A  where id  in (select aid from B  where id = 3)

产生的原因:因为查询过程中，多个id放在了一个字段，这个字段不止有数字也有逗号,id是数字类型,所以数据库识别以后直接会报非法数字。

解决方法

先将子查询转成多行

	WITH 
    split_string AS (
		        SELECT   (select aid from B  where id = 3)AS string FROM dual
    )
SELECT 
    REGEXP_SUBSTR(string, '[^,]+', 1, LEVEL) AS aid
FROM 
    split_string
CONNECT BY
    REGEXP_SUBSTR(string, '[^,]+', 1, LEVEL) IS NOT NULL;

再次查询A表数据

select * from A  where id  in (	WITH 
    split_string AS (
		        SELECT   (select aid from B  where id = 3)AS string FROM dual
    )
SELECT 
    REGEXP_SUBSTR(string, '[^,]+', 1, LEVEL) AS aid
FROM 
    split_string
CONNECT BY
    REGEXP_SUBSTR(string, '[^,]+', 1, LEVEL) IS NOT NULL)

将A表的名称转成一行

select LISTAGG(name,',') WITHIN GROUP (ORDER BY name) 关联流程 from A where  id in (	WITH 
    split_string AS (
        SELECT   (select aid from B  where id = 3)AS string FROM dual
    )
SELECT 
    REGEXP_SUBSTR(string, '[^,]+', 1, LEVEL) AS split_value
FROM 
    split_string
CONNECT BY
    REGEXP_SUBSTR(string, '[^,]+', 1, LEVEL) IS NOT NULL)