[转]oracle的ANYDATA数据类型

本文转自：http://blog.csdn.net/yuzhenhuan01/article/details/6606106

ANYDATA数据类型是个有点奇特的类型，你可以把不同数据类型的数据通过转换插入该类型的字段中，这个特性可以适应一些特殊的需求，不过插入和查询这个字段时稍有点繁琐。

由下语句看出ANYDATA是一个TYPE：

SQL> SELECT object_name, object_type  FROM dba_objects WHERE object_name like '%ANYDATA%' AND owner = 'SYS';

OBJECT_NAME                                                                      OBJECT_TYPE
-------------------------------------------------------------------------------- -------------------
ANYDATA                                                                          TYPE
ANYDATA                                                                          TYPE BODY
ANYDATASET                                                                       TYPE
ANYDATASET                                                                       TYPE BODY
DBMS_ANYDATASET_LIB                                                              LIBRARY
DBMS_ANYDATA_LIB                                                                 LIBRARY
STREAMS$_ANYDATA_ARRAY                                                           TYPE

7 rows selected

我们来看下这个TYPE可以使用的一些东西：

SQL> DESC ANYDATA;
Element             Type
------------------- ---------
CONVERTNUMBER       FUNCTION
CONVERTDATE         FUNCTION
CONVERTCHAR         FUNCTION
CONVERTVARCHAR      FUNCTION
CONVERTVARCHAR2     FUNCTION
CONVERTRAW          FUNCTION
CONVERTBLOB         FUNCTION
CONVERTCLOB         FUNCTION
CONVERTBFILE        FUNCTION
CONVERTOBJECT       FUNCTION
CONVERTREF          FUNCTION
CONVERTCOLLECTION   FUNCTION
BEGINCREATE         PROCEDURE
PIECEWISE           PROCEDURE
SETNUMBER           PROCEDURE
SETDATE             PROCEDURE
SETCHAR             PROCEDURE
SETVARCHAR          PROCEDURE
SETVARCHAR2         PROCEDURE
SETRAW              PROCEDURE
SETBLOB             PROCEDURE
SETCLOB             PROCEDURE
SETBFILE            PROCEDURE
SETOBJECT           PROCEDURE
SETREF              PROCEDURE
SETCOLLECTION       PROCEDURE
ENDCREATE           PROCEDURE
GETTYPENAME         FUNCTION
GETTYPE             FUNCTION
GETNUMBER           FUNCTION
GETDATE             FUNCTION
GETCHAR             FUNCTION
GETVARCHAR          FUNCTION
GETVARCHAR2         FUNCTION
GETRAW              FUNCTION
GETBLOB             FUNCTION
GETCLOB             FUNCTION
GETBFILE            FUNCTION
GETOBJECT           FUNCTION
GETREF              FUNCTION
GETCOLLECTION       FUNCTION
CONVERTTIMESTAMP    FUNCTION
CONVERTTIMESTAMPTZ  FUNCTION
CONVERTTIMESTAMPLTZ FUNCTION
CONVERTINTERVALYM   FUNCTION
CONVERTINTERVALDS   FUNCTION
CONVERTNCHAR        FUNCTION
CONVERTNVARCHAR2    FUNCTION
CONVERTNCLOB        FUNCTION
SETTIMESTAMP        PROCEDURE
SETTIMESTAMPTZ      PROCEDURE
SETTIMESTAMPLTZ     PROCEDURE
SETINTERVALYM       PROCEDURE
SETINTERVALDS       PROCEDURE
SETNCHAR            PROCEDURE
SETNVARCHAR2        PROCEDURE
SETNCLOB            PROCEDURE
GETTIMESTAMP        FUNCTION
GETTIMESTAMPTZ      FUNCTION
GETTIMESTAMPLTZ     FUNCTION
GETINTERVALYM       FUNCTION
GETINTERVALDS       FUNCTION
GETNCHAR            FUNCTION
GETNVARCHAR2        FUNCTION
GETNCLOB            FUNCTION
ACCESSNUMBER        FUNCTION
ACCESSDATE          FUNCTION
ACCESSCHAR          FUNCTION
ACCESSVARCHAR       FUNCTION
ACCESSVARCHAR2      FUNCTION
ACCESSRAW           FUNCTION
ACCESSBLOB          FUNCTION
ACCESSCLOB          FUNCTION
ACCESSBFILE         FUNCTION
ACCESSTIMESTAMP     FUNCTION
ACCESSTIMESTAMPTZ   FUNCTION
ACCESSTIMESTAMPLTZ  FUNCTION
ACCESSINTERVALYM    FUNCTION
ACCESSINTERVALDS    FUNCTION
ACCESSNCHAR         FUNCTION
ACCESSNVARCHAR2     FUNCTION
ACCESSNCLOB         FUNCTION
CONVERTBFLOAT       FUNCTION
CONVERTBDOUBLE      FUNCTION
CONVERTUROWID       FUNCTION
SETBFLOAT           PROCEDURE
SETBDOUBLE          PROCEDURE
GETBFLOAT           FUNCTION
GETBDOUBLE          FUNCTION
ACCESSBFLOAT        FUNCTION
ACCESSBDOUBLE       FUNCTION
ACCESSUROWID        FUNCTION  

大多从字面上都可以看出这些方法的功能

下面创建一个包含该类型的字段的测试表
SQL> CREATE TABLE yutest (v_cl1 sys.anyData);

Table created

desc一下：
SQL> desc yutest;
Name  Type        Nullable Default Comments
----- ----------- -------- ------- --------
V_CL1 SYS.ANYDATA Y                         

插入几条测试数据，注意这里使用的相应的方法函数插入：
SQL> INSERT INTO yutest VALUES (sys.anyData.convertNumber(5));

1 row inserted

SQL> INSERT INTO yutest VALUES (sys.anyData.convertDate(SYSDATE));

1 row inserted

SQL> INSERT INTO yutest VALUES (sys.anyData.convertVarchar2('test'));

1 row inserted

SQL> commit;

Commit complete

直接查询表中数据：
SQL> SELECT *    FROM yutest a;

V_CL1
-----
<Obje
<Obje
<Obje
 查不出来具体的数据，看来必须转换下才能查看了。

这个是查看各个数据行的数据类型的：

这个是错的
SQL> SELECT v_cl1.gettypeName()    FROM yutest;

SELECT v_cl1.gettypeName()    FROM yutest

ORA-00904: "V_CL1"."GETTYPENAME": 标识符无效

这个也是错的
SQL> SELECT yutest.v_cl1.gettypeName()    FROM yutest;

SELECT yutest.v_cl1.gettypeName()    FROM yutest

ORA-00904: "YUTEST"."V_CL1"."GETTYPENAME": 标识符无效

这个才是正确的查询方法

SQL> SELECT a.v_cl1.gettypeName()    FROM yutest a;

A.V_CL1.GETTYPENAME()
--------------------------------------------------------------------------------
SYS.NUMBER
SYS.DATE
SYS.VARCHAR2

 示例中涉及了3个数据类型，我这里也简单是写个转换函数，也只转换了3个类型

CREATE OR REPLACE FUNCTION getanydata(v_data IN sys.anyData)
  RETURN VARCHAR2 IS
  v_num     NUMBER;
  v_date    DATE;
  v_re_data VARCHAR2(4000);
BEGIN
  CASE v_data.gettypeName
    WHEN 'SYS.NUMBER' THEN
      IF (v_data.getNumber(v_num) = dbms_types.success) THEN
        v_re_data := v_num;
      END IF;
    WHEN 'SYS.DATE' THEN
      IF (v_data.getDate(v_date) = dbms_types.success) THEN
        v_re_data := v_date;
      END IF;
    WHEN 'SYS.VARCHAR2' THEN
      IF (v_data.getVarchar2(v_re_data) = dbms_types.success) THEN
        NULL;
      END IF;
    ELSE
      v_re_data := 'not number or date or varchar2';
  END CASE;

  RETURN v_re_data;
END getanydata;

使用新建的函数来查询

SQL> SELECT getanydata(v_cl1) FROM yutest a;

GETANYDATA(V_CL1)
--------------------------------------------------------------------------------
5
14-7月 -11
test

数据有了