How do I copy or clone or duplicate the data, structure, and indices of a MySQL table to a new one?
This is what I've found so far.
This will copy the data and the structure, but not the indices:
create table {new_table} select * from {old_table};
This will copy the structure and indices, but not the data:
create table {new_table} like {old_table};
To copy with indexes and triggers do these 2 queries:
CREATE TABLE newtable LIKE oldtable;
INSERT newtable SELECT * FROM oldtable;
To copy just structure and data use this one:
CREATE TABLE tbl_new AS SELECT * FROM tbl_old;
I've asked this before:
Apart from the solution above, you can use AS
to make it in one line.
CREATE TABLE tbl_new AS SELECT * FROM tbl_old;
MySQL way:
CREATE TABLE recipes_new LIKE production.recipes;
INSERT recipes_new SELECT * FROM production.recipes;
I found the same situation and the approach which I took was as follows:
- Execute
SHOW CREATE TABLE <table name to clone>
: This will give you theCreate Table
syntax for the table which you want to clone - Run the
CREATE TABLE
query by changing the table name to clone the table.
This will create exact replica of the table which you want to clone along with indexes. The only thing which you then need is to rename the indexes (if required).
After I tried the solution above, I come up with my own way.
My solution a little manual and needs DBMS.
First, export the data.
Second, open the export data.
Third, replace old table name with new table name.
Fourth, change all the trigger name in the data (I use MySQL and it show error when I don't change trigger name).
Fifth, import your edited SQL data to the database.
The better way to duplicate a table is using only DDL
statement. In this way, independently from the number of records in the table, you can perform the duplication instantly.
My purpose is:
DROP TABLE IF EXISTS table_name_OLD;
CREATE TABLE table_name_NEW LIKE table_name;
RENAME TABLE table_name TO table_name_OLD;
RENAME TABLE table_name _NEW TO table_name;
This avoids the INSERT AS SELECT
statement that, in case of table with a lot of records can take time to be executed.
I suggest also to create a PLSQL procedure as the following example:
DELIMITER //
CREATE PROCEDURE backup_table(tbl_name varchar(255))
BEGIN
-- DROP TABLE IF EXISTS GLS_DEVICES_OLD;
SET @query = concat('DROP TABLE IF EXISTS ',tbl_name,'_OLD');
PREPARE stmt FROM @query;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
-- CREATE TABLE GLS_DEVICES_NEW LIKE GLS_DEVICES;
SET @query = concat('CREATE TABLE ',tbl_name,'_NEW LIKE ',tbl_name);
PREPARE stmt FROM @query;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
-- RENAME TABLE GLS_DEVICES TO GLS_DEVICES_OLD;
SET @query = concat('RENAME TABLE ',tbl_name,' TO ',tbl_name,'_OLD');
PREPARE stmt FROM @query;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
-- RENAME TABLE GLS_DEVICES_NEW TO GLS_DEVICES;
SET @query = concat('RENAME TABLE ',tbl_name,'_NEW TO ',tbl_name);
PREPARE stmt FROM @query;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END//
DELIMITER ;
Have a nice day! Alex
Expanding on this answer one could use a stored procedure:
CALL duplicate_table('tableName');
Which will result in a duplicate table called tableName_20181022235959
If called when
SELECT NOW();
results:
2018-10-22 23:59:59
Implementation
DELIMITER $$
CREATE PROCEDURE duplicate_table(IN tableName VARCHAR(255))
BEGIN
DECLARE schemaName VARCHAR(255) DEFAULT SCHEMA();
DECLARE today VARCHAR(14) DEFAULT REPLACE(REPLACE(REPLACE(NOW(), '-', ''), ' ', ''), ':', ''); -- update @ year 10000
DECLARE backupTableName VARCHAR(255) DEFAULT CONCAT(tableName, '_', today);
IF fn_table_exists(schemaName, tableName)
THEN
CALL statement(CONCAT('CREATE TABLE IF NOT EXISTS ', backupTableName,' LIKE ', tableName));
CALL statement(CONCAT('INSERT INTO ', backupTableName,' SELECT * FROM ', tableName));
CALL statement(CONCAT('CHECKSUM TABLE ', backupTableName,', ', tableName));
ELSE
SELECT CONCAT('ERROR: Table "', tableName, '" does not exist in the schema "', schemaName, '".') AS ErrorMessage;
END IF;
END $$
DELIMITER ;
DELIMITER $$
CREATE FUNCTION fn_table_exists(schemaName VARCHAR(255), tableName VARCHAR(255))
RETURNS TINYINT(1)
BEGIN
DECLARE totalTablesCount INT DEFAULT (
SELECT COUNT(*)
FROM information_schema.TABLES
WHERE (TABLE_SCHEMA COLLATE utf8_general_ci = schemaName COLLATE utf8_general_ci)
AND (TABLE_NAME COLLATE utf8_general_ci = tableName COLLATE utf8_general_ci)
);
RETURN IF(
totalTablesCount > 0,
TRUE,
FALSE
);
END $$
DELIMITER ;
DELIMITER $$
CREATE PROCEDURE statement(IN dynamic_statement TEXT)
BEGIN
SET @dynamic_statement := dynamic_statement;
PREPARE prepared_statement FROM @dynamic_statement;
EXECUTE prepared_statement;
DEALLOCATE PREPARE prepared_statement;
END $$
DELIMITER ;
Try this :
`CREATE TABLE new-table (id INT(11) auto_increment primary key) SELECT old-table.name, old-table.group, old-table.floor, old-table.age from old-table;`
I selected 4 columns from old-table and made a new table.
FOR MySQL
CREATE TABLE newtable LIKE oldtable ;
INSERT newtable SELECT * FROM oldtable ;
FOR MSSQL
Use MyDatabase
:
Select * into newCustomersTable from oldCustomersTable;
This SQL is used for copying tables, here the contents of oldCustomersTable will be copied to newCustomersTable
.
Make sure the newCustomersTable
does not exist in the database.
来源:https://stackoverflow.com/questions/3280006/duplicating-a-mysql-table-indices-and-data