pgsql存储函数string_to_array跟unnest在dm8中如何实现

看下这样符合要求不？

CREATE OR REPLACE TYPE simple_string AS OBJECT (
    value VARCHAR2(100) -- 字符串类型
);
CREATE OR REPLACE TYPE string_table IS TABLE OF simple_string;
CREATE OR REPLACE FUNCTION unnest(
    p_unnest VARCHAR2,
    p_delimiter VARCHAR2
) RETURN string_table
AS
    result string_table := string_table(); -- 初始化结果
BEGIN
    FOR r IN (
        SELECT REGEXP_SUBSTR(p_unnest, '[^'||p_delimiter||']+', 1, LEVEL) AS value
        FROM DUAL
        CONNECT BY REGEXP_SUBSTR(p_unnest, '[^'||p_delimiter||']+', 1, LEVEL) IS NOT NULL
    ) LOOP
        result.EXTEND(); -- 扩展数组
        result(result.COUNT) := simple_string(r.value); -- 添加新值
    END LOOP;

    RETURN result; -- 返回结果
END unnest;
/

SELECT * FROM TABLE(unnest('weq,eweq,ewqe,d', ','));

直接sql查询也是可以的

SELECT REGEXP_SUBSTR('weq,eweq,ewqe,d', '[^,]+', 1, LEVEL) AS value
FROM DUAL
CONNECT BY REGEXP_SUBSTR('weq,eweq,ewqe,d', '[^,]+', 1, LEVEL) IS NOT NULL;