Question

考虑以下脚本：

CREATE TYPE t1 AS TABLE OF VARCHAR2(10);
/
CREATE TYPE t2 AS VARRAY(10) OF VARCHAR2(10);
/

CREATE TABLE t (
  id NUMBER(10),
  t1 t1,
  t2 t2
)
NESTED TABLE t1 STORE AS t1_nt;

INSERT INTO t VALUES (1, NULL, NULL);
INSERT INTO t VALUES (2, t1('abc'), t2('abc'));

SELECT * FROM t WHERE 'abc' MEMBER OF t1;
SELECT * FROM t WHERE 'abc' MEMBER OF t2;

最后两个SELECT语句的输出为

ID    T1      T2
-------------------
2     [abc]   [abc]

ORA-00932: inconsistent datatypes: expected UDT got 
SQL_XQMZQAMSETXZLGIEEEEBUTFWF.T2

The documentation claims that this operation should be possible for varrays as well as for nested tables：

member_condition是成员资格条件，用于测试元素是否为嵌套表的成员。如果expr等于指定的嵌套表或varray的成员，则返回值为TRUE。

我在做什么错了？

Answer 1

这是一个文档错误，请参见此AskTom question and answer。

一种解决方法是运行此查询：

SELECT *
FROM t
WHERE EXISTS (
  SELECT 1 FROM TABLE(t2) WHERE column_value = 'abc'
)

I've written up a blog post showing emulations of all the multiset conditions and operators，以防其他人觉得有用。

在SQL中将Oracle MEMBER OF运算符与VARRAY列一起使用

1 个答案: