Oracle Create Table AS and table comments and column comments

Question

Is it possible to create another table as CREATE TABLE AS and also preserve columns' comments ?

CREATE TABLE TABLE1_COPY AS SELECT * FROM TABLE1;

The previous statement does not include columns' comments. Therefore TABLE1_COPY is left without columns' comments. Is using USER_COL_COMMENTS the only way to reproduce the same comments on my newly created table too?

Answer 1

As for DMBS_METADATA.GET_DDL it doesn't seem to genereate COMMENT ON COLUMN statements unless I am missing some properties.

One method is to use dbms_metadata.get_dependent_ddl in combination with dbms_metadata.get_ddl

Here is an example created using SQL plus:

SQL> set long 1000000

SQL> create table t (x number);

Table created.

SQL> comment on column T.X IS 'this is the column comment';

Comment created.

SQL> comment on table T IS 'this is the table comment';

Comment created.

SQL> SELECT dbms_metadata.get_ddl( 'TABLE', 'T' ) || ' ' ||
  2         dbms_metadata.get_dependent_ddl( 'COMMENT', 'T', USER ) the_ddl
  3  FROM dual
  4  /

THE_DDL
--------------------------------------------------------------------------------

  CREATE TABLE "SCOTT"."T"
   (    "X" NUMBER
   ) SEGMENT CREATION DEFERRED
  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
  TABLESPACE "USERS"

   COMMENT ON COLUMN "SCOTT"."T"."X" IS 'this is the column comment'

   COMMENT ON TABLE "SCOTT"."T"  IS 'this is the table comment'