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 过程来确定我的 SELECT 查询的结果集中的列使用了哪些数据类型。但不幸的是，通过这种方式，我只能得到 Oracle 数据类型 (record.col_type) - 1、8、12 等的代码。

所以我想知道，如何轻松获得与返回数据类型代码（即 VARCHAR2、LONG、DATE 等）等效的字符串，而不是其数字代码？

Answer 1

这是一个稍微笨拙的解决方案，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 as tbone suggests。

Answer 2

试试：

select 
   distinct
   c.type# type_code,
   decode(c.type#, 1, decode(c.charsetform, 2, 'NVARCHAR2', 'VARCHAR2'),
                   2, decode(c.scale, null, decode(c.precision#, null, 'NUMBER', 'FLOAT'), 'NUMBER'),
                   8, 'LONG',
                   9, decode(c.charsetform, 2, 'NCHAR VARYING', 'VARCHAR'),
                   12, 'DATE',
                   23, 'RAW', 24, 'LONG RAW',
                   69, 'ROWID',
                   96, decode(c.charsetform, 2, 'NCHAR', 'CHAR'),
                   100, 'BINARY_FLOAT',
                   101, 'BINARY_DOUBLE',
                   105, 'MLSLABEL',
                   106, 'MLSLABEL',
                   111, 'REF',
                   112, decode(c.charsetform, 2, 'NCLOB', 'CLOB'),
                   113, 'BLOB', 114, 'BFILE', 115, 'CFILE',
                   121, 'USER_TYPE',
                   122, 'USER_TYPE',
                   123, 'USER_TYPE',
                   178, 'TIME(' ||c.scale|| ')',
                   179, 'TIME(' ||c.scale|| ')' || ' WITH TIME ZONE',
                   180, 'TIMESTAMP(' ||c.scale|| ')',
                   181, 'TIMESTAMP(' ||c.scale|| ')'||' WITH TIME ZONE',
                   231, 'TIMESTAMP(' ||c.scale|| ')'||' WITH LOCAL TIME ZONE',
                   182, 'INTERVAL YEAR(' ||c.precision#||') TO MONTH',
                   183, 'INTERVAL DAY(' ||c.precision#||') TO SECOND(' ||
                         c.scale || ')',
                   208, 'UROWID',
                   'UNDEFINED') type_name from sys.col$ c order by c.type#;

Answer 3

使用ANYDATA.GetTypeName

这是一个带有一些解释和示例的链接：http://www.oracle-developer.net/display.php?id=218

我引用：

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.

这里是some examples of using this in a select。

Answer 4

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;

另外请注意，109 是用户定义的类型，您可能需要改用 DESCRIBE_COLUMNS3。