生成创建table 的sql sed ‘s/REM //‘

Purpose:
========

The purpose of this article is to explain how you can transfer table
definitions from one database to another database by generating script 
files.

 
How to Generate 'CREATE TABLE' Scripts from Existing Tables:
============================================================

If basic tables, that is, tables with no partitions, constraints, indexes,
etc. are sufficient for your purposes, then you can use the script listed 
at the end of this article.

If you need detailed CREATE TABLE SQL statements, then you can follow 
this example:

   exp user_name/password file=table_name.dmp rows=n tables=\('table_name'\);
     (Use brackets to escape the backslash because of shell interpretation.)

   imp user_name/password file= table_name.dmp indexfile=table_name.log

   on UNIX:
     sed 's/REM //' table_name.log >table_name.sql
   on another platforms:
     open file table_name.log in any text editor and replace string 'REM ' by '' 
     (empty string).
	 save as table_name.sql
	 
Check the file table_name.sql for the script that you need.


============ Script for basic CREATE TABLE SQL statement ================
spool table.lst
set serveroutput on size 1000000
declare
starting boolean :=true;
r_owner varchar2(30) := '&1';
r_table_name varchar2(30) := '&2';
begin 
dbms_output.put_line('create table '||r_owner||'.'||r_table_name||'(');
for r in (select column_name, data_type, data_length, data_precision, data_scale, data_default, nullable 
            from all_tab_columns
           where table_name = upper(r_table_name)
		     and owner=upper(r_owner)
		   order by column_id)
loop
  if starting then
    starting:=false;
  else
    dbms_output.put_line(',');	
  end if;

  if r.data_type='NUMBER' then
    if r.data_scale is null then
      dbms_output.put(r.column_name||' NUMBER('||r.data_precision||')');  	
    else
      dbms_output.put(r.column_name||' NUMBER('||r.data_precision||','||r.data_scale||')');
    end if;
  else if r.data_type = 'DATE' then
    dbms_output.put_line(r.column_name||' DATE');
  else if instr(r.data_type, 'CHAR') >0 then
    dbms_output.put(r.column_name||' '||r.data_type||'('||r.data_length||')');
  else
    dbms_output.put(r.column_name||' '||r.data_type);
  end if;
  end if;
  end if;
  if r.data_default is not null then
    dbms_output.put(' DEFAULT '||r.data_default);
  end if;
  if r.nullable = 'N' then
    dbms_output.put(' NOT NULL ');
  end if;
end loop;
dbms_output.put_line(' ); ');
end;
/

spool off