MySQL Copy Table With Examples

 MySQL Copy Table With Examples

Summary: in this tutorial, you will learn how to copy tables within the same database or from one database to another using CREATE TABLE and SELECT statements.

MySQL copy the table to a new table

Copying data from an existing table to a new one is very useful in some cases such as backing up data and replicating the production data for testing.

To copy data from a table to a new table, you use CREATE TABLE and SELECT statements as follows:

CREATE TABLE new_table 
SELECT col, col2, col3 
FROM
    existing_table;

First, MySQL creates a new table with the name indicated in the CREATE TABLE statement. The structure of the new table is defined by the result set of the SELECT statement. Then, MySQL populates data that comes from the SELECT statement to the new table.

To copy partial data from an existing table to the new one, you use the WHERE clause in the SELECT statement as follows:

CREATE TABLE new_table 
SELECT col1, col2, col3 
FROM
    existing_table
WHERE
    conditions;

It is very important to check whether the table you want to create already exists before creating it. To do so, you use IF NOT EXIST a clause in the CREATE TABLE statement. The complete command of copying data from an existing table to the new one is as follows:

CREATE TABLE new_table 
SELECT col1, col2, col3 
FROM
    existing_table
WHERE
    conditions;

Note that the statement above just copies the table and its data. It does not copy other database objects such as indexes, primary key constraint, foreign key constraints, triggers, etc., associated with the table.

To copy data from one table and also all the dependent objects of the table, you use the following statements:

CREATE TABLE IF NOT EXISTS new_table LIKE existing_table;

INSERT new_table
SELECT * FROM existing_table;

We need to execute two statements. The first statement creates a new table new_table by duplicating the existing_table. The second statement inserts data from the existing table into the new_table.

MySQL copy table examples

The following statement copies data from the offices table to a new table named offices_bk in the classicmodels sample database.

CREATE TABLE IF NOT EXISTS offices_bk 
SELECT * FROM
    offices;

We can verify the copy by querying data from the office_bk table as follows:

SELECT
    *
FROM
    offices_bk;

In cases we want to copy the offices in the US only, we can add the WHERE clause to the SELECT a statement as follows:

CREATE TABLE IF NOT EXISTS offices_usa 
SELECT * 
FROM
    offices
WHERE
    country = 'USA'

The following statement gets all data from the offices_usa table.

SELECT 
    *
FROM
    offices_usa;

Suppose, we want to copy not only the data but also all database objects associated with the offices table, we use the following statements:

CREATE TABLE offices_dup LIKE offices;

INSERT office_dup
SELECT * FROM offices;

MySQL copy table to another database

Sometimes, you want to copy a table to a different database. In such cases you use the following statements:

CREATE TABLE destination_db.new_table 
LIKE source_db.existing_table;

INSERT destination_db.new_table 
SELECT *
FROM source_db.existing_table;

The first statement creates a new table new_table in the destination database (destination_db) by duplicating the existing table (existing_table) from the source database (source_db).

The second statements copy data from the existing table in the source database to the new table in the destination database.

Let’s see the following example.

First, we create a database named testdb using the following statement:

CREATE DATABASE IF NOT EXISTS testdb;

Second, we create the offices table in the testdb by copying its structure from the offices table in the classicmodels database.

CREATE TABLE testdb.offices LIKE classicmodels.offices;

Third, we copy data from the classimodels.offices table to testdb.offices table.

INSERT testdb.offices
SELECT *
FROM classicmodels.offices;

Let’s verify the data from the testdb.offices table.

SELECT
    *
FROM
    testdb.offices;

In this tutorial, we have shown you various techniques to copy tables within a database and from one database to another.