如何通过代码确定Oracle数据类型的字符串值？

Question

我使用DBMS_SQL.DESCRIBE_COLUMNS过程来确定哪些数据类型用于我的SELECT查询的结果集中的列.但不幸的是,通过这种方式,我只能获得Oracle数据类型(record.col_type)的代码- ) - 1,8,12等.

所以我想知道,我怎样才能轻松获得一个等效的返回数据类型代码(即VARCHAR2,LONG,DATE等)而不是数字代码？

Answer 1

这是一个稍微笨重的解决方案,但您可以使用CASE语句来"查找"数据类型描述.

case record.col_type
  when dbms_types.TYPECODE_DATE then 'DATE'             
  when dbms_types.TYPECODE_NUMBER then 'NUMBER'           
  when dbms_types.TYPECODE_RAW then 'RAW'              
  when dbms_types.TYPECODE_CHAR then 'CHAR'             
  when dbms_types.TYPECODE_VARCHAR2 then 'VARCHAR2'         
  when dbms_types.TYPECODE_VARCHAR then 'VARCHAR'          
  when dbms_types.TYPECODE_MLSLABEL then 'MLSLABEL'         
  when dbms_types.TYPECODE_BLOB then 'BLOB'             
  when dbms_types.TYPECODE_BFILE then 'BFILE'            
  when dbms_types.TYPECODE_CLOB then 'CLOB'              
  when dbms_types.TYPECODE_CFILE then 'CFILE'            
  when dbms_types.TYPECODE_TIMESTAMP then 'TIMESTAMP'        
  when dbms_types.TYPECODE_TIMESTAMP_TZ then 'TIMESTAMP_TZ'     
  when dbms_types.TYPECODE_TIMESTAMP_LTZ then 'TIMESTAMP_LTZ'    
  when dbms_types.TYPECODE_INTERVAL_YM then 'INTERVAL_YM'      
  when dbms_types.TYPECODE_INTERVAL_DS then 'INTERVAL_DS'      
  when dbms_types.TYPECODE_REF then 'REF'              
  when dbms_types.TYPECODE_OBJECT then 'OBJECT'           
  when dbms_types.TYPECODE_VARRAY then 'VARRAY'                       
  when dbms_types.TYPECODE_TABLE then 'TABLE'                        
  when dbms_types.TYPECODE_NAMEDCOLLECTION then 'NAMEDCOLLECTION'  
  when dbms_types.TYPECODE_OPAQUE then 'OPAQUE'                            
  when dbms_types.TYPECODE_NCHAR then 'NCHAR'            
  when dbms_types.TYPECODE_NVARCHAR2 then 'NVARCHAR2'       
  when dbms_types.TYPECODE_NCLOB then 'NCLOB'                  
  when dbms_types.TYPECODE_BFLOAT then 'BFLOAT'           
  when dbms_types.TYPECODE_BDOUBLE then 'BDOUBLE'          
  when dbms_types.TYPECODE_UROWID then 'UROWID'              
end case

要获取此值,您应该查询数据字典,如tbone建议的那样.

Answer 2

查看DBMS_TYPES包(来自我的11gr2):

select text from all_source
where owner='SYS'
and name='DBMS_TYPES'
and type='PACKAGE';

PACKAGE dbms_types AS

  TYPECODE_DATE            PLS_INTEGER :=  12;

  TYPECODE_NUMBER          PLS_INTEGER :=   2;

  TYPECODE_RAW             PLS_INTEGER :=  95;

  TYPECODE_CHAR            PLS_INTEGER :=  96;

  TYPECODE_VARCHAR2        PLS_INTEGER :=   9;

  TYPECODE_VARCHAR         PLS_INTEGER :=   1;

  TYPECODE_MLSLABEL        PLS_INTEGER := 105;

  TYPECODE_BLOB            PLS_INTEGER := 113;

  TYPECODE_BFILE           PLS_INTEGER := 114;

  TYPECODE_CLOB            PLS_INTEGER := 112;

  TYPECODE_CFILE           PLS_INTEGER := 115;

  TYPECODE_TIMESTAMP       PLS_INTEGER := 187;

  TYPECODE_TIMESTAMP_TZ    PLS_INTEGER := 188;

  TYPECODE_TIMESTAMP_LTZ   PLS_INTEGER := 232;

  TYPECODE_INTERVAL_YM     PLS_INTEGER := 189;

  TYPECODE_INTERVAL_DS     PLS_INTEGER := 190;



  TYPECODE_REF             PLS_INTEGER := 110;

  TYPECODE_OBJECT          PLS_INTEGER := 108;

  TYPECODE_VARRAY          PLS_INTEGER := 247;            /* COLLECTION TYPE */

  TYPECODE_TABLE           PLS_INTEGER := 248;            /* COLLECTION TYPE */

  TYPECODE_NAMEDCOLLECTION PLS_INTEGER := 122;

  TYPECODE_OPAQUE          PLS_INTEGER := 58;                 /* OPAQUE TYPE */



  /* NOTE: These typecodes are for use in AnyData api only and are short forms

     for the corresponding char typecodes with a charset form of SQLCS_NCHAR.

  */

  TYPECODE_NCHAR           PLS_INTEGER := 286;

  TYPECODE_NVARCHAR2       PLS_INTEGER := 287;

  TYPECODE_NCLOB           PLS_INTEGER := 288;



  /* Typecodes for Binary Float, Binary Double and Urowid. */

  TYPECODE_BFLOAT          PLS_INTEGER := 100;

  TYPECODE_BDOUBLE         PLS_INTEGER := 101;

  TYPECODE_UROWID          PLS_INTEGER := 104;



  SUCCESS                  PLS_INTEGER := 0;

  NO_DATA                  PLS_INTEGER := 100;

另请注意,109是用户定义的类型,您可能需要使用DESCRIBE_COLUMNS3.

Answer 3

使用 ANYDATA.GetTypeName

这里有一些解释和示例的链接:http://www.oracle-developer.net/display.php？id = 218

我引述:

SQL> DECLARE
  2     v_anydata  ANYDATA := ANYDATA.ConvertVarchar2('String');
  3     v_typename VARCHAR2(128);
  4  BEGIN
  5     v_typename := v_anydata.GetTypeName();
  6     DBMS_OUTPUT.PUT_LINE('Type of ANYDATA instance is [' || v_typename || ']');
  7  END;
  8  /

Type of ANYDATA instance is [SYS.VARCHAR2]

PL/SQL procedure successfully completed.

以下是在select中使用它的一些示例.