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Thread: create new table based on an existing table

  1. #1
    Join Date
    Aug 2000
    I want to create a new table with all the data from an existing table. I understand that I can use
    create table new_table_name
    select * from old_table

    But I want to check whether there is any row in the old_table first. Can this be done in sql? Thanks, Rong

  2. #2
    Join Date
    May 2000
    Portsmouth, NH, USA

    Thumbs up yes

    looks good.

    to check if data exists in Table_1 just use:
    select count(*) from Table_1;

    if you get at least an output of "1" then there is at least one row in the table.

    then just use the:
    create table Table_2
    AS select *
    from Table_1;

  3. #3
    Join Date
    May 2000
    Richardson, Texas, USA
    Just a tip:

    I case the table contains too many rows the following
    will save some time:

    select count(*) from Table_1 where rownum=1;

    If it returns 1 then the table has row(s) inside it, if 0 then it's empty. It'll run really fast since it checks only the first row.



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