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