记录类型反射/填充未知类型的记录变量(PL/SQL)

Question

我有一个包，里面有一个记录类型和该类型的变量：

CREATE PACKAGE my_package AS
  TYPE t_rec IS RECORD(
    id           NUMBER,
    name         VARCHAR2(100),
    last_updated DATE
  );
  v_var t_rec;
END;

我想创建一个通用的过程来填充任何记录变量，所以它可以这样调用：

BEGIN
  populate_record('my_package.v_var', 'MY_TABLE', CHARTOROWID(:VAR1));
END;

该程序的逻辑可能看起来是这样的：

PROCEDURE populate_record(
  p_var_name   IN VARCHAR2,
  p_table_name IN VARCHAR2,
  p_rowid      IN ROWID
) IS
BEGIN
  -- determining a type of a given record variable
  -- determining names and data types of given record variable's columns
  -- selecting a row from a given table by a given rowid
  -- filling out a given record variable by mapping table columns
  --   to record columns by their names (using dynamic PL/SQL)
END;

但我不知道如何获得有关某一特定记录的信息。是否有用于查询记录类型列的数据字典视图或内置函数
谢谢

p.S.:11.2

更新的

我找到了一种使用PL/Scope:获取记录信息的方法

CREATE OR REPLACE VIEW user_record_types AS
SELECT
  i.object_name package_name,
  i.name type_name
FROM
  user_identifiers i
WHERE
  i.object_type = 'PACKAGE'
  AND i.type = 'RECORD'
  AND i.usage = 'DECLARATION'
/
CREATE OR REPLACE VIEW user_record_types_columns AS
SELECT
  i1.object_name package_name,
  i1.name type_name,
  ROW_NUMBER() OVER (
    PARTITION BY
      i1.object_name,
      i1.name
    ORDER BY
      i2.usage_id
  ) column_num,
  i2.name column_name,
  i3.name column_type,
  i3.type column_type_class
FROM
  user_identifiers i1,
  user_identifiers i2,
  user_identifiers i3
WHERE
  i1.object_type = 'PACKAGE'
  AND i1.type = 'RECORD'
  AND i1.usage = 'DECLARATION'
  AND i2.object_name = i1.object_name
  AND i2.object_type = i1.object_type
  AND i2.type = 'VARIABLE'
  AND i2.usage = 'DECLARATION'
  AND i2.usage_context_id = i1.usage_id
  AND i3.object_name = i2.object_name
  AND i3.object_type = i2.object_type
  AND i3.usage = 'REFERENCE'
  AND i3.usage_context_id = i2.usage_id
/
CREATE OR REPLACE VIEW user_record_variables AS
SELECT
  i1.object_name package_name,
  i1.name variable_name,
  CASE i2.type
    WHEN 'RECORD' THEN
      i2.object_name
    WHEN 'PACKAGE' THEN
      i2.name
  END type_package_name,
  CASE i2.type
    WHEN 'RECORD' THEN
      i2.name
    WHEN 'PACKAGE' THEN
      i3.name
  END type_name
FROM
  user_identifiers i1,
  user_identifiers i2,
  user_identifiers i3
WHERE
  i1.object_type = 'PACKAGE'
  AND i1.type = 'VARIABLE'
  AND i1.usage = 'DECLARATION'
  AND i2.object_name = i1.object_name
  AND i2.object_type = i1.object_type
  AND i2.type IN ('RECORD', 'PACKAGE')
  AND i2.usage = 'REFERENCE'
  AND i2.usage_context_id = i1.usage_id
  AND i3.object_name (+) = i2.object_name
  AND i3.object_type (+) = i2.object_type
  AND i3.type (+) = 'RECORD'
  AND i3.usage (+) = 'REFERENCE'
  AND i3.usage_context_id (+) = i2.usage_id
/

但是当我使用%ROWTYPE时有一个问题，因为没有关于%ROWTYPE是什么的信息。所以我认为PL/Scope不是一个完整的解决方案。。。

Answer 1

如果您有访问权限，可以尝试使用表user_identifiers或all_identifiers，如其他SO文章所示。

您可能需要重新编译您的包：

alter package  my_types compile plscope_settings='IDENTIFIERS:ALL' reuse settings;

不幸的是，这只适用于11gR1。