我们正在测试Oracle，并负责在Oracle上构建所有数据库对象（表，proc，触发器等），并且当前使用Microsoft SQL Server 2008
R2。我们几乎对所有ID列都使用uniqueidentifier。我使用此函数来创建GUID：

CREATE OR REPLACE FUNCTION NEWID RETURN CHAR IS guid CHAR(36) ;
BEGIN
    SELECT SYS_GUID() INTO guid FROM DUAL;
    guid :=
               SUBSTR(guid,  1, 8) ||
        '-' || SUBSTR(guid,  9, 4) ||
        '-' || SUBSTR(guid, 13, 4) ||
        '-' || SUBSTR(guid, 17, 4) ||
        '-' || SUBSTR(guid, 21);
    RETURN guid;
END NEWID;
/

但是现在我无法弄清楚如何在创建表时将其用作列的默认值。这是一个不起作用的示例：

CREATE TABLE "NonWorkingExample"
(   
  "ID"                              CHAR(36)      NOT NULL DEFAULT   NEWID(),
  "UnitNumber"                      NUMBER(38)    NOT NULL,
  "StartDateTime"                   TIMESTAMP     NOT NULL,
  "EndDateTime"                     TIMESTAMP     NULL,

  CONSTRAINT PK_RentalAgreements  PRIMARY KEY ("ID")
);

错误：

Error starting at line 1 in command:
CREATE TABLE "NonWorkingExample"
(   
  "ID"                          CHAR(36)      NOT NULL DEFAULT NEWID(),
  "UnitNumber"                  NUMBER(38)    NOT NULL,
  "StartDateTime"               TIMESTAMP     NOT NULL,
  "EndDateTime"                 TIMESTAMP     NULL,

  CONSTRAINT PK_RentalAgreements  PRIMARY KEY ("ID")
)
Error at Command Line:3 Column:58
Error report:
SQL Error: ORA-00907: missing right parenthesis
00907. 00000 -  "missing right parenthesis"
*Cause:    
*Action:

任何帮助将非常感激。谢谢你。