Oracle - pl sql 从 SYS_REFCURSOR 中选择

Question

我有一个返回 SYS_REFCURSOR 的函数，该函数具有单行但多列。我想要做的是能够使用 SYS_REFCURSOR 中返回的列值进行具有嵌套子查询的 SQL 查询。诸如类型等替代想法将不胜感激。下面的代码是我即时编写的，尚未经过语法验证。

--Oracle function
CREATE DummyFunction(dummyValue AS NUMBER) RETURN SYS_REFCURSOR
IS
  RETURN_DATA SYS_REFCURSOR;
BEGIN
  OPEN RETURN_DATA
  SELECT
    TO_CHAR(dummyValue) || 'A' AS ColumnA
    ,TO_CHAR(dummyValue) || 'B' AS ColumnB
  FROM
    DUAL;

  RETURN RETURN_DATA;
END;

--sample query with sub-queries; does not work
SELECT
  SELECT ColumnA FROM DummyFunction(1) FROM DUAL AS ColumnA
  ,SELECT ColumnB FROM DummyFunction(1) FROM DUAL AS ColumnB
FROM
  DUAL;

Answer 1

SYS_REFCURSOR 不适用于预期用途 - 您需要创建一个 Oracle 类型：

CREATE TYPE your_type IS OBJECT (
  ColumnA VARCHAR2(100),
  ColumnB VARCHAR2(100)
)

更新您的函数：

CREATE DummyFunction(dummyValue AS NUMBER) 
RETURN your_type
IS

BEGIN

  INSERT INTO your_type
  SELECT TO_CHAR(dummyValue) || 'A' AS ColumnA,
         TO_CHAR(dummyValue) || 'B' AS ColumnB
    FROM DUAL;

  RETURN your_type;

END;

然后您可以使用：

SELECT (SELECT ColumnA FROM table(DummyFunction(1))) AS ColumnA, 
       (SELECT ColumnB FROM table(DummyFunction(1))) AS ColumnB
  FROM DUAL

该示例过于复杂 - 您需要使用的是：

SELECT x.columna,
       x.columnb
  FROM table(DummyFunction(1)) x