CODEWITHSUNDEEP
sqloracle-database
reforrer
reforrer

Reputation: 745

Oracle Create Table AS and table comments and column comments

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?

Upvotes: 6

Views: 22196

Answers (2)

street hawk
street hawk

Reputation: 625

This is a copy of the above solution in a simple way, the difference is there is no USER provided. Where TABLE_NAME is an existing table.

SELECT dbms_metadata.get_ddl( 'TABLE','TABLE_NAME' ) || ' ' || dbms_metadata.get_dependent_ddl( 'COMMENT', 'TABLE_NAME' ) the_ddl FROM dual;

If you are using 'Oracle SQL Developer', the above query is not necessary because you can directly get the result query from the 'SQL' tab itself. The steps are -

  1. Click on the table you want to copy.
  2. On the right panel go to 'SQL' tab. You will get the same result.

Upvotes: 0

Ian Carpenter
Ian Carpenter

Reputation: 8626

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'

Upvotes: 15

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