Script for automatic creation of DB tables - database

Question

I have to make a script which creates schema that must have 1.000 tables, with 1.000 columns.
Table name (example): TABLE_058
Column name (example): T058_COL_078
Tables should be empty. I'm working with Oracle DB and ain't too apt with SQL/PL-SQL.
Would be much obliged if someone would point me in right direction.

Answer 1

This will work if you save it as a script and then execute it under SQL*Plus. The tables are named TABLE_000 through TABLE_999 and the columns are similarly sequenced 000 through 999.
SET ECHO OFF
SET TERMOUT OFF
SET TRIMSPOOL ON
SET PAGESIZE 0
SET LINESIZE 2000
SET FEEDBACK OFF
SPOOL C:\CreateTables.sql
SELECT
CASE
WHEN ColIndex = 0 THEN 'CREATE TABLE TABLE_' || TO_CHAR(TableIndex, 'FM000') || ' ('
ELSE NULL
END ||
' T' || TO_CHAR(TableIndex, 'FM000') || '_COL_' || TO_CHAR(ColIndex, 'FM000') || ' VARCHAR2(1)' ||
CASE
WHEN ColIndex = 999 THEN ');'
ELSE ','
END
FROM (
SELECT TableIndex, ColIndex FROM (
SELECT LEVEL - 1 AS TableIndex FROM DUAL CONNECT BY LEVEL <= 1000)
CROSS JOIN (
SELECT LEVEL - 1 AS ColIndex FROM DUAL CONNECT BY LEVEL <= 1000)
ORDER BY TableIndex, ColIndex);
SPOOL OFF
Some things to note:
The numbering scheme is from 000 through 999 because your template for table/column names uses three digits and the only way to get to 1000 tables/columns like that is to start at zero.
Change the filename in SPOOL C:\CreateTables.sql to a filename that works for you.
You didn't specify the column type so the script above has them all as VARCHAR2(1)
It's important to run the above as a script from SQL*Plus. If you don't, a lot of the SQL*Plus chatter will end up in the spooled output. To run the script from SQL*Plus, just type the "at" sign (#) followed by the script's name. If you name it TableGenScript.sql then do this:
SQL> #TableGenScript.sql
The first few lines of output from the script look like this:
CREATE TABLE TABLE_000 ( T000_COL_000 VARCHAR2(1),
T000_COL_001 VARCHAR2(1),
T000_COL_002 VARCHAR2(1),
T000_COL_003 VARCHAR2(1),
Give it a try and you should be able to tweak this to your specific needs.
Addendum NikolaB asked how to vary the column type and the answer is too long to fit in a comment...
To vary the column type, take the part of the query that says || ' VARCHAR2(1)' || and replace it with your data-type logic. For example, if columns 0-599 are VARCHAR2, columns 600-899 are NUMBER, and columns 900-999 are DATE, change the script to something like this:
... all the SETs like above, then the SPOOL ...
SELECT
CASE
WHEN ColIndex = 0 THEN 'CREATE TABLE TABLE_' || TO_CHAR(TableIndex, 'FM000') || ' ('
ELSE NULL
END ||
' T' || TO_CHAR(TableIndex, 'FM000') || '_COL_' || TO_CHAR(ColIndex, 'FM000') ||
CASE -- put the data-type logic in this CASE
WHEN ColIndex BETWEEN 0 AND 599 THEN ' VARCHAR2(1)'
WHEN ColIndex BETWEEN 600 AND 899 THEN ' NUMBER'
ELSE ' DATE'
END || -- data-type logic ends here and original query resumes
CASE
WHEN ColIndex = 999 THEN ');'
ELSE ','
END
FROM
... and then the same as above, all the way through to the SPOOL OFF
I've highlighted the CASE statement with a comment. If you put your data-type logic between the CASE and the END you should be fine.

Answer 2

Export the schema's metadata.
exp userid=user/pass#db owner=someowner rows=n file=somefile.dmp
if you open the file using notepad you could see the DML statements.
you can then import using
imp userid=user/pass#otherdb file=somefile.dmp full=y
you can also copy to another schema on the same db (usually for testing)
imp userid=user/pass#db file=somefile.dmp fromuser=someschema touser=otherschema
you can also use the new datapump for parallel and compression enhancements.
check out this link