语法：

DBMS_METADATA.GET_DDL (
object_type     IN VARCHAR2,
name               IN VARCHAR2,
schema           IN VARCHAR2 DEFAULT NULL,
version            IN VARCHAR2 DEFAULT 'COMPATIBLE',
model              IN VARCHAR2 DEFAULT 'ORACLE',
transform        IN VARCHAR2 DEFAULT 'DDL')
RETURN CLOB;

示例：select dbms_metadata.get_ddl('TABLE','EMP','SCOTT') from dual;

SQL> select dbms_metadata.get_ddl('TABLE','EMP','SCOTT') from dual;

DBMS_METADATA.GET_DDL('TABLE','EMP','SCOTT')
--------------------------------------------

  CREATE TABLE "SCOTT"."EMP"
   (    "EMPNO" NUMBER(4,0),
        "ENAME" VARCHAR2(10),

--设置LONG和pagesize后能完全显示
SQL> SET LONG 2000000
SQL> SET PAGESIZE 0
SQL> select dbms_metadata.get_ddl('TABLE','EMP','SCOTT') from dual;

  CREATE TABLE "SCOTT"."EMP"
   (    "EMPNO" NUMBER(4,0),
        "ENAME" VARCHAR2(10),
        "JOB" VARCHAR2(9),
        "MGR" NUMBER(4,0),
        "HIREDATE" DATE,
        "SAL" NUMBER(7,2),
        "COMM" NUMBER(7,2),
        "DEPTNO" NUMBER(2,0),
         CONSTRAINT "PK_EMP" PRIMARY KEY ("EMPNO")
  USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT
 CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS"  ENABLE,
         CONSTRAINT "FK_DEPTNO" FOREIGN KEY ("DEPTNO")
          REFERENCES "SCOTT"."DEPT" ("DEPTNO") ENABLE
   ) SEGMENT CREATION IMMEDIATE
  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS"