MySQL Clone Tables

MySQL Clone Tables

There may be a situation when you need an exact copy of a table and CREATE TABLE … SELECT doesn’t suit your purposes because the copy must include the same indexes, default values, and so forth.

You can handle this situation by following steps:

  • Use SHOW CREATE TABLE to get a CREATE TABLE statement that specifies the source table’s structure, indexes and all.
  • Modify the statement to change the table name to that of the clone table and execute the statement. This way, you will have exact clone table.
  • Optionally, if you need the table contents copied as well, issue an INSERT INTO … SELECT statement, too.

Example:

Try out the following example to create a clone table for tutorials_tbl.

Step 1:

Get complete structure about table.

mysql> SHOW CREATE TABLE tutorials_tbl G;
*************************** 1. row ***************************
       Table: tutorials_tbl
Create Table: CREATE TABLE `tutorials_tbl` (
  `tutorial_id` int(11) NOT NULL auto_increment,
  `tutorial_title` varchar(100) NOT NULL default '',
  `tutorial_author` varchar(40) NOT NULL default '',
  `submission_date` date default NULL,
  PRIMARY KEY  (`tutorial_id`),
  UNIQUE KEY `AUTHOR_INDEX` (`tutorial_author`)
) TYPE=MyISAM
1 row in set (0.00 sec)

ERROR:
No query specified

Step 2:

Rename this table and create another table.

mysql> CREATE TABLE `clone_tbl` (
  -> `tutorial_id` int(11) NOT NULL auto_increment,
  -> `tutorial_title` varchar(100) NOT NULL default '',
  -> `tutorial_author` varchar(40) NOT NULL default '',
  -> `submission_date` date default NULL,
  -> PRIMARY KEY  (`tutorial_id`),
  -> UNIQUE KEY `AUTHOR_INDEX` (`tutorial_author`)
-> ) TYPE=MyISAM;
Query OK, 0 rows affected (1.80 sec)

Step 3:

After executing step 2, you will create a clone table in your database. If you want to copy data from old table then you can do it by using INSERT INTO… SELECT statement.

mysql> INSERT INTO clone_tbl (tutorial_id,
    ->                        tutorial_title,
    ->                        tutorial_author,
    ->                        submission_date)
    -> SELECT tutorial_id,tutorial_title,
    ->        tutorial_author,submission_date
    -> FROM tutorials_tbl;
Query OK, 3 rows affected (0.07 sec)
Records: 3  Duplicates: 0  Warnings: 0

Finally, you will have exact clone table as you wanted to have.

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